Mihi Claves, The First Ally

Indestructible & Prime(At the beginning of your
upkeep, add one mana of this creatures color identity
to your pool. This mana is not lost as steps and phases
end.)
This creature costs {1} for each Ally in your
graveyard.
When an Ally creature enters your graveyard you
may pay {p/w}{p/w}. If you do, exile that creature then
Mihi Claves perpetually gains +1/+1 and has the abilities of the creatures exiled this way.