Eternal Bond

Indestructible.

Whenever a creature you control dies, you gain 2 life and put a +1/+1 counter on another creature you control.
If a creature you control would be put into a graveyard, exile it instead with a bond counter on it. You may cast creatures exiled with bond counters by paying their mana cost. When you do, add {g} or {b} to your mana pool.