Okay, I’ve already mentioned how to deal with Shago, for the most part, but I suppose I can go into detail.
To start, his divekick is NOT an overhead, which means you can block it low, unlike normal jumping attacks. So, you can block his slide, his divekick, his projectiles, AND his DP all while blocking low (that’s ALL of his specials). That only leaves him his regular jump-in attacks, his overhead-hitting axe-kick command normal (which is slow and reactable), and his throw (which he can also get from a dash-cancel). You can still block all of these with a high block if you so choose, but his slide will likely get you.
If you see him jump, block high to prevent the overhead from a normal jump-in attack ('cause at that point, he’s not going to slide - you just got to watch for a follow-up low normal when he lands - and if he does that, then you can low block it and likely shadow counter his next attack if you happen to have meter yourself; remember that - it’s good advice regardless of which character you’re fighting).
If you see him dash forward, hold back to block, but also be ready to tech his throw by readying a throw input yourself. You can also back-dash or neutral jump to avoid a throw, but that’s risky if he dash cancels into his DP, so I don’t recommend that course of action.
If he has enough meter for a surge, expect him to use it (it makes a lot of his specials safe) - keep an eye on it, because that will let you know how long to hold your block (hold it down longer if he uses it), otherwise, go ham if he doesn’t have it. If he hits you with his throw or some surged moves, he can juggle you, however, once he does, he’ll be forced to perform a light, medium, or heavy manual followed by an axe kick to recapture you. You can break his manuals with a good read/reaction, but it’s risky due to a potential lockout. So, I recommend waiting for the axe-kick. It’s easier to break, but also carries its own risks - for example, he may simply not do it and/or do something else instead.
His overhead axe-kick can be a nuisance to be sure, but he can only do it at a certain range, so if he’s far away you don’t have to worry about it. Furthermore, if he does it in a combo, you can break it with a heavy combo-breaker since it’s so slow (watch out for counter-breakers though).
His projectiles are really, really fast, but do next to no damage, so if Shago tries to zone you with those, sit tight and wait for an opening. He’ll get shadow/surge meter eventually, but once he does, he’ll want to use it. Wait for him to get in close and waste it, then hit him where it hurts if no other opportunity presents itself before then.
His divekick can cross-up, but only if he’s within half-screen or so - that’s when you want to be ready to reverse your block.
In regards to the Shago matchup, good luck.
Gargos actually has a glaring weakness - he’s vulnerable up close on wakeup. You have to pressure him by getting in his face. Sure, he may be intimidating, but it’s only a farce until he gets his minions.
If he command grabs you, you can break the followup manual hits while he holds you - a headbutt is a light combo-break; a punch to the gut is a medium combo-break; a knee to the gut is a heavy combo-break. If he chooses to either tele-slam you throw to the ground, drop you, or absorb your shadow, those are unbreakable (sadly). If he tries to command grab you out of the air or during a combo, you can also break/tech the initlal grab with a light combo-breaker. Be aware that he can command grab you up close (light), leap forward and command grab you (medium), or command grab you while you’re in the air (heavy).
His portal punches are considered projectiles, so any projectile invincible move should be able to avoid it. Conversely, you can bide your time by blocking it, and dashing in closer during the moves recovery (and still have time to block or avoid a follow-up portal punch). If he combos you: the portal punch that appears beneath your feet or at your ankles can be broken with a light combo-breaker; If it appears in front of you, that’s medium; if it appears above your face or above your head, that’s a heavy. Many Gargos players like to hit you with the heavy or the portal punch ender to bounce you and then juggle you closer with the light portal punch that appears underneath so that they can then put you in range of his command grab - be ready to break those lights (but also be aware that he can also counter-break you) or the command grab (since it’ll be in a combo). If he has shadow meter, watch out for the shadow portal punch, which comes out fast and can stop you mid-move or mid-jump, as well as be used as a combo-opener. If he uses it mid-combo, you can break it - it’s 1 of the easiest shadow moves in the game to break. Of course, like with all things, he can counter-break, but knowing it’s easy to combo-break, you can bait the counter by only pressing it once, and forcing him to drop his combo, leaving him exposed.
If he uses his charge (I forget the name of it), simply block and be aware of in-air follow-ups since he’ll often bounce off of you. The shadow version is slow and easy to block, so punish that right away if you block it. Also, it’s an overhead, so block high.
Minions can be tough, there’s no doubt about that, but they have to get in close to hit you, unless Gargos throws 1 at you (which I find is incredibly rare). Sit back and poke them with your light attacks to limit your exposure to Gargos who will try to use them to open you up. Watch for his command grab as he gets closer, otherwise, block anything he throws at you. Remember, the skinny 1 takes 2 separate hits; the fat 1 takes 3. Learn the timing of their attacks to find your openings and watch for their special moves that Gargos may try to use against you (the latter pins you down, while the other hits with a delayed overhead attack).
When Gargos uses his instinct, he gets infinite armor for as long as the instinct lasts, which means you can hit him to your heart’s content and he won’t flinch. To counter this, you can either a) throw him, or b) hit him with a grounded heavy normal attack (such as standing or crouching heavy punch or kick), which can immediately put him at a disadvantage, since his instinct doesn’t allow him to block. He might explode to prevent you from taking advantage, but that’s okay since he loses half his instinct in the process and it does no damage whatsoever (but watch for followup setups, since it’ll knock you down on hit).
Gargos only has 3 auto-doubles - learn them so you can break them!
Eyedol’s a bit hard to fight right now, because even the devs think he’s unbalanced right now. You see, his jumping heavy punch is really powerful. It does damage, it comes out fast, it has a big hitbox, it recovers quickly and puts him at advantage, AND it bounces for a juggle opportunity. It will, thankfully get patched in some way soon though - the devs will be seeing to that (they’ve confirmed this). Until then, avoid this attack at all costs!
On hit with his jumping heavy punch, a lot of Eyedol players like to follow it up either with his medium overhead attack, or his medium or heavy DP. The former recaptures and the other 2 allow for juggles. Be ready to break these on reaction. What’s interesting is that any of these can be followed up by ANOTHER DP, so be ready to break those too if you don’t make an attempt to break the 1st set during a combo, since that seems to be a rather popular setup with him right now.
Like Gargos, Eyedol also has 3 auto-doubles. Learn them so you can break him more effectively!
His shadow mallet (when he hits the ground with his mace) can be shadow-countered, just about anywhere during the move due to how slow it is, so if you block it, do it for a free combo punish. His normal mace slam, however, is fast and relatively safe (I think), so be careful with that one. His mace slam ender either sets up a juggle or causes a hard knockdown (I can’t recall which; I will check this and re-edit and/or someone will undoubtedly correct me).
His shoulder charge is punishable on block as well, but be careful because the shadow version is projectile invulnerable. This ender is his wall-splat ender, so watch for follow-up grabs.
His DP is powerful for the reasons mentioned above: his heavy recaptures, his medium sets him up for a juggle, and what I didn’t tell you before is that his light DP has invincible startup frames. If he’s close to you on wakeup (after you knock him down), watch for this, block it, and punish as he comes back down. The shadow version is both invincible and recaptures. Keep in mind, however, that the medium and heavy versions are NOT invincible. His DP is his damage ender in warrior stance (and I think sets him up for juggles too, if I’m not mistaken - again, I’ll double check this and edit and/or someone will undoubtedly correct me).
His forward charge is easily blockable, punishable, and shadow-counterable. However, he can use a rage charge to cancel it mid-move into a jump or a dash, so be wary if he has those charges - otherwise, punish away.
Watch for his command grab - it does no damage, but gets him mage charge, which makes his mage’s specials more powerful. It also leaves him at advantage, making it easier for him to hit you with a followup attack such as a poke into combo, another command grab, or a regular grab. Like with Gargos, he can grab you up close (light) or leap forward and grab you (medium). The good news, unlike Gargos, he can’t use it to grab you out of the air or use it while he himself is in the air. Instead, he can back-dash, then leap forward and grab you, as kind of a pseudo-fake out (heavy).
While in mage stance, he will attempt to zone you out. His bolt strike can hit you low (block it low) along the ground, strike you out of the air while you jump (medium) or hit you up close (heavy). Blocking low stops all of these, but if he hits you, he can follow it up with another bolt-strike or use his teleport for a free no-damage rage charge. If he has mage charges, he can make his bolt strike more effective by doing more than 1 at the same time, but they can still be blocked. His bolt-strike ender gives him more shadow meter.
The problem with blocking low is not the bolt-strike, but his meteors, which hit overhead. Be ready to switch your blocks from low to high if you think he’s going to drop 1 (or more with mage charges) on your head, or vice-versa if he starts with a meteor and goes into a bolt-strike. Thankfully, his shadow meteors don’t hit overhead, so as powerful as those are, you won’t have to worry about how you block them. His meteor ender is his damage ender.
His teleport does no damage, but gives him rage charges if used correctly. It’s easy to do too, since he can immediately use it on a hit (or even on block with some of his other attacks, like his long-range medium command normal). However, it has a slow startup, so you can punish it as he does it (assuming you didn’t get hit or block an attack beforehand) and is also punishable on recovery if you successfully block the attack. He can teleport in front your behind you, so be ready for either 1. If he hits you because you guessed wrong, don’t worry too much about it. He just put himself closer to you, making himself easier to punish, and he can’t use his rage charges until he switches his stance back to warrior.
His ground stomp in mage is the worst of his attacks, since it’s easily blocked (high or low), but be careful as it’s got range and can be used as a good pressure tool up close) and can be used to start combos. If he uses the stomp as an ender, it juggles, so be ready to break any anti-air he may throw at you (most likely a crouching heavy punch, which shoots up at a 45-degree angle).
While in instinct, Gargos can use his special attacks from both stances at the same time. His mace slam pairs with his bolt strike, his shoulder charge pairs with his hoof stomp, and his DP pairs with his meteors. Just keep in mind the properties of both attacks as he does them, while in instinct. for example, if he attacks you with a light DP, he’ll also throw out a close meteor. This means it’ll hit mid and overhead AND be invincible during startup, so you’ll want to block high. Conversely, if he does a light mace slam, he’ll also do a low bolt-strike, so you’ll want to block this low. And so on… Also, watch for his shadow moves, which will hit 10x instead of 5x, since he does both versions of the shadow attacks, either at the same time (as with the mallet slam and bolt strike) or 1 after the other (as with his DP/meteor storm and shoulder charge/hoof stomp). He can also use this time to punch himself in the face to keep his instinct active. Use this opportunity to punish him, if he does that (conveniently, he’ll also be hurting himself in the process).
I hope that helps you with your matchups! Wooh, I need to give my fingers a rest… 
If anyone notices any errors in my post, feel free to correct me, for @Pazzmanian’s benefit. 
Keep in mind i was just finished getting wrecked for the last hour before the post