Centurion

The Centurion is a tanky Zard encountered only in Hard Black Citadel. Although he doesn't have much different stats than the Crusader, he provides something that other Zards don't.

Centurion doubles all nearby enemies' speeds, most notably the Hyperknight, who combined with the Centurion, reaches your base in less than 3 seconds! Things may be chaotic, but I trust your defense is amazing to have gotten this far. AoE towers will do well due to the insane speed clumping the enemies all up together, though make sure you have a building draw all the enemies' attention to the same spot.

Notably, Zargoyles are unable to receive this speed buff due to how far up they are. Sometimes, they will receive the buff when they are low enough to the ground.