Subject Phobos

Trample, haste, first strike, hexproof
When a creature dealt combat damage by Subject Phobos this turn dies, put a number of +1/+1 counter on Subject Phobos equal to that creatures power. Subject Phobos then deals damage equal to that creatures toughness to another target creature.
Khan was finally satisfied with Subject Phobos, using it as a weapon in the field.