Sycor is the boss of the Laboratory area. It's inhabiting a giant body but has a spare one in Eastern Tower. Defeating it causes the next room to be booby-trapped but unlocks one of two 'gates' to the Map System.
This boss uses the Undead Core's A.I.
According to The Guardian Beasts, it's capable of speech and possesses sentience.
It seems to possess a code of honour of sorts, refusing to attack the Castle Master's minions.
It's fight in the Tower is one of the few optional fights in the game.