Sycor is the stage boss of the Laboratory area, who inhabits a grey mechanical body. It speaks in Old English, and is surrounded by red cores. The red cores turn green, which allow Serenity to jump on them and then attack Sycor when it's faces appear.
Once defeated, it'll reveal that has a different body and will ask for a rematch. The next room has a nasty trap (several charge shots which deal 10 damage) but surviving it allows the player to venture, eventually reaching the Reservoir. but unlocks one of two 'gates' to the Map System.
The rematch against Sycor at the East Tower is far more difficult. It's appearance remains the same, though it's now accompanied by corrupted versions of Ignis and Shinica. In addition, riding it's mini-cores is now mandatory because the bottom floor is now covered with insta-kill spikes.
Energy Blast (Fires these off at regular intervals. Can be dodged by jumping over them or moving to the platform at the very left.
Charged Energy Blast (Uses this attack at low health, is indicated by a charging sound followed by several energy blasts that deal 10 damage.)
Warning Shot (Sycor's opening move, fires a large blast of energy at the top and bottom of the screen, which must be jumped over. Deals 10 damage. Sycor doesn't use this move during the rematch)
After being defeated by Serenity Horton, he is killed, but does not mind and is happy to be freed.
During the first Sycor battle, the cores are green when ridden on (and turn red occasionally); they're pinkish-red when you fight Scyor in the East Tower. The reason for this is unknown.
Sycor's personality seems to differ in his first fight and his second one. In his debut appearance, he speaks in Old English and seems honorable; in his rematch, he speaks in Modern English and seems to be an insane, sadistic individual who corrupts Ignis and Shinicia, claiming that it was part of a prophecy. This is either an oversight, an implication that Sycor 2 is Sycor's actual personality and that his honourable persona is a façade or that the Sycor you fight in the Laboratory and the East Tower are two different individuals.
This boss is one of two bosses to be a palette swap of the Core/Undead Core, along with Graildyn. It also uses an easier version of the Undead Core's AI.
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, as well as the hardest. It's also the only boss in the game, where the player can choose which battle theme Scyor has (via terminals early on in the East Tower).