Heroic Intervention has had a few reprints of late that have dropped its price a bit, but it's still ten dollars and something any green deck would want
Whenever one or more other creatures you control enter, if one or more of them entered from a graveyard or was cast from a graveyard, put a +1/+1 counter on each creature you control.
you no longer need to worry about an opponent who sweeps it aside with Wrath of God or whatever everybody else does to handle your legendary board, so its easier to rebuild
It also comes with the Evasive keyword - making it harder to challenge - and the power to quest for two lore to help you to victory
For example, if you control The Ozolith ("Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.") when Sin's last ability resolves, you'll put the appropriate number of each kind of counter onto both The Ozolith and the target creature