If your deck revolves around having many creatures in play, this is what you need
Knock Out your opponents last Pokmon in play
Regrettably, Tithe is on the Reserved List, so it is ridiculously expensive for the effect you get, but if you want an inexpensive alternative that is slightly watered down, Gift of Estates plays reasonably well, trading instant speed and doubling its mana cost for a guaranteed 3 plains cards
This creature enters with three +1/+1 counters on it
This can make Cresselia a sponge, but after three Energy and other Pokemon to set up, why would you ever attach more Energy to it
Yes, there's people crazy enough to fill out an entire deck with Krakens, Leviathans, Octopuses, and Serpents, slapping a commander like Thassa, God of the Sea, Slinn Voda, the Rising Deep, or (my favorite!) Arixmethes, Slumbering Isle, and then smashing face with giant sea monsters