>>718541572
Most of the old games' lore is just "creepy evil eyeball demon causes trouble, Kirby travels different worlds and then kills it". It was starting in Return to Dreamland that an established continuity began, and previous characters started to make more reappearances instead of just be one-offs.

One of the story points was a blue butterfly would appear in the intros of every game. Come towards the end of one of the boss gauntlets in Star Allies the butterfly reappeared, landed on a defeated superboss and consumed it, then transformed into the superboss Morpho Knight. Morpho Knight would reappear again in Forgotten Land as the butterfly, doing the same thing to the main villain. That butterfly is the grim reaper for defeated warriors, claiming their lives and souls to take physical form and battle Kirby.