25 Jan 2019
If either target is an illegal target as Savage Smash resolves, neither creature will deal or be dealt damage.
25 Jan 2019
You can’t cast Savage Smash unless you choose both a creature you control and a creature you don’t control as targets.
25 Jan 2019
If the creature you control is an illegal target as Savage Smash tries to resolve, it won’t get +2/+2. If that creature is a legal target but the other creature isn’t, the creature you control still gets +2/+2.