Illusive Shadow

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Whenever a creature you control dies this
turn, create a token that's a copy of that
creature, except it's a blue illusion with:
"This creature can't block," and: "When this
creature becomes the target of a spell or ability,
sacrifice it." Put a +1/+1 counter on that
token.