Murtagh Morzansson

First Strike

Whenever you cast an instant or sorcery spell, target creature you control get +X/+0 until end of turn,
where X is that spells mana value if this is the first
time this ability has resolved this turn. Otherwise,
you may pay {x}. When you do, Murtagh deals X
damage to target nonlegendary creature.

Partner with Thorn, Riders Companion