Through the Breach

If all of the spell’s targets are illegal when the spell tries to resolve, it won’t resolve and none of its effects will happen.

You reveal all cards you intend to splice at the same time. Each individual card can be spliced only once onto any one spell.

A card with a splice ability can’t be spliced onto itself because the spell is on the stack (and not in your hand) when you reveal the cards you want to splice onto it.