Nature's Blessings

Whenever a creature enters the battlefield under your control, you may have target opponent gain
3 life. If you do, that creature enters with an additional two +1/+1 counters.
Contingency Whenever a creature you control attacks, if it had a +1/+1 counter on it, you may remove a counter from that creature. If you do add X {g} mana to your mana pool for each counter removed this way at the beginning of
your next main phase.