Muramasa, Soul Gatherer

Muramasa can be your commander.
Whenever equipped creature dies, exile it with a Soul
counter.

Equipped creature has +1/+1 for each creature card in
exile with a Soul counter on it.
As long as one of those creatures cards has flying,
equipped creature has flying. The same is true for first
strike, double strike, deathtouch, haste, hexproof,
indestructible, lifelink, menace, protection, reach, trample
and vigilance.

Equip {1}