Divine Assistance

Cumulative upkeep {3}{w}
At the beginning of your upkeep you may put
two 1/1 creature tokens into play with first
strike, or add two +1/+1 counters to creatures
you control, or do one of each.
~ 2/2 tokens you control gain vigilance.
~ 3/3 tokens you control gain trample.
~ 4/4 tokens you control gain flying.
(Tokens retain abilities previously gained)
If the combined power of your tokens is greater
than 20, sacrifice Divine Assistance.