Heroics

Heroics may only enchant human creatures.
Enchanted creature gains Heroic - Add a +1/+1 counter to it. When enchanted creature dies, transfer Heroics to target creature.
Whenever a legendary creature is destroyed solely due to damage from a human creature, that human creature gains Heroic.
He saw, already one in Heav'n was plac'd,
And one with more than mortal triumphs grac'd
-Ovid, Metamorphoses