mtg why are conspiracy cards banned Why was it banned for

Three Tree Mascot

It will give all friendly creatures +5/+5, a much bigger boost than Elves are used to getting from cards like Elvish Archdruid or Elvish Champion

Even if it's only one creature, in dedicated landfall decks, this gives you a guaranteed way to hit all of your landfall triggers each turn, even if the trample is irrelevant

Whenever another non-token creature you control dies, you may exile it if you do, you create a 1/1 white Gingerbread creature token that's a copy of that creature, except it loses all other card types and becomes a Food artifact in addition to its other types

Raven's Crime is optimal for a long game especially when lands can be recurred through means such as Tilling Treefolk