Dusk

A spell with aftermath cast from a graveyard will always be exiled afterward, whether it resolves, it's countered, or it leaves the stack in some other way.

All split cards have two card faces on a single card, and you put a split card onto the stack with only the half you're casting. The characteristics of the half of the card you didn't cast are ignored while the spell is on the stack. For example, if an effect prevents you from casting green spells, you can cast Destined of Destined // Lead, but not Lead.

If another effect allows you to cast a split card with aftermath from a graveyard, you may cast either half. If you cast the half that has aftermath, you'll exile the card if it would leave the stack.