From WiKirby, your independent source of Kirby knowledge.
Mace Knight is part of the Mid-Boss Meta-Knights in Kirby's Adventure and Kirby Super Star, as well as their respective remakes, Kirby: Nightmare in Dream Land and Kirby Super Star Ultra. He is seen on the Halberd and on Aquarius.
Mace Knight is the toughest of the four Meta-Knights, taking many hits to defeat, though he is still easily inhaled. Despite his name, he actually attacks with a flail, not a mace. He swings the flail over his head and occasionally throws it, causing it to fly a considerable distance to the left or right before returning to him. His flail is capable of blocking certain attacks, particularly ones that cannot penetrate. Mace Knight cannot jump, meaning that if he is knocked down to a lower area, he cannot get back up again.
Kirby's Adventure/Kirby:Nightmare in Dream Land
Mace Knight debuts as a member of the Meta-Knights mid-boss in Kirby's Adventure and its remake, Kirby: Nightmare in Dream Land. He is fought alongside the other group members Axe Knight, Javelin Knight, and Trident Knight. During the battle, he will swing his flail over his head and thrust it at Kirby. He can be defeated with Copy Abilities or by simply inhaling him, though he has more stamina than the other knights.
Kirby Super Star (Ultra)
Mace Knight re-appears in Kirby Super Star and its remake Kirby Super Star Ultra with a similar role to that of its previous outing, battle-wise. However, in the sub-game Revenge of Meta Knight, he has a speaking role along with Axe Knight and the other members of the Halberd crew, commenting as Kirby completes his task of destroying the Halberd. He is mainly in charge of giving updates on the Halberd's condition and is also tasked with firing up the main cannon. Additionally, if Kirby finds the secret room on the ship with lots of food and 1-Ups, Mace Knight will reveal that the stash of goodies in said room belongs to him, and expresses much sadness as Kirby eats it all.
Kirby Mass Attack
In Kirby Mass Attack, Mace Knight is fought along with the other Meta-Knights at the end of Stage 4 in the sub-game Strato Patrol EOS. In this mode, his only attack is swinging his flail around. In addition to damaging Kirbys, the flail can block shots fired from them. Mace Knight also appears in Kirby Quest. Similarly to Strato Patrol EOS, he is battled with the rest of the Meta-Knights in Chapter 3.
Kirby: Planet Robobot
Mace Knight makes a cameo in the Kirby: Planet Robobot sub-game Meta Knightmare Returns. When Meta Knight uses his Meta Knightmares attack, Mace Knight appears with the rest of the Meta-Knights to defeat all on-screen foes.
Artwork from Kirby's Adventure