Case of the Shifting Visage
Enchantment — Case
Oracle Text
At the beginning of your upkeep, surveil 1.
To solve — There are fifteen or more cards in your graveyard. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast a nonlegendary creature spell, copy that spell. (The copy becomes a token.)
Watch Out
This triggers when the spell is cast, before it resolves. Even if the spell is countered, the cast trigger still resolves. Copies of spells are not cast, so they won't trigger this.
This card involves continuous effects applied in layer order. Type changes (layer 4) are applied before ability changes (layer 6) and P/T changes (layer 7). The order matters — a creature that loses abilities in layer 6 can still get new abilities from effects applied later in the same layer.