sen·tient
ˈsen(t)SH(ē)ənt/
adjective
able to perceive or feel things.
Fulgore 2013 bio/story - Protocols reactivated. Enhanced system bootstrap complete. A new Fulgore prototype is online, with a singular directive: ELIMINATE ENEMIES TO ULTRATECH. However, the mind of the machine is different. It plans. It feels. It is aware. It is somehow… human.
Just based on that alone I would say yes.
His endings…
Spare Orchid, ULTRA Fulgore:
SYSTEM MALFUNCTION. KILLING BLOW ABORTED. How can a machine know mercy? Fulgore cannot ignore his imperative to destroy but human “memories” interfere with his machine logic. Unable to digest the echoes of a fighting spirit, Fulgore attempts to process his true nature.
Spare Fulgore, ULTRA Orchid:
PROTOTYPE. APPROVED. Echoes of a lost humanity have been purged from Fulgore’s systems. The sum of what remains is a merciless machine, driven to destroy. Without a cycle spared to savor his victories, Fulgore begins a search for his next adversary.
ULTRA Both Orchid and Fulgore:
Thousands of Fulgores have been created, only to be destroyed, remade, and improved upon… But this one is different. Individuality and independence now race through his circuits. Still a killing machine, Fulgore rejects his coded imperatives and ponders his next target.
His first ending seems to hint that he is sentient due to knowing mercy. His second one seems to be a what-if of what would happen if he manages to purge all of Eagle’s influence on him and doesn’t really say anything about if he feels or not. His third one mentions individuality and independence, him rejecting his coded imperatives and even him pondering his next opponent, meaning he actually thinks and is able to make his own decisions to some extent.
So his mini bio and 2 out of 3 endings imply he can either feel feelings and/or think and make decisions. So IMO the answer is yes.