Ramp is great and this effect is unique at a measly one mana, so it doesn't surprise me that it's nearing $10, jokes aside
For 2 of any Energy (meaning you could run this in a mixed deck), you can do up to 200 damage and risk only 1 Prize card
"Harley Quinn Card Collection V
The "once per turn" clause is a bit of a bummer, but probably necessary to prevent easy infinite combos
Being on the board allows it to protect each of your other monsters from destruction effects or battle destruction
2) From Deck recipe PDF version (February 2013)[edit] New Atlantean Mermail Deck Weaknesses[edit] Cards that prevent searching or Special Summoning from the Deck, such as "Thunder King Rai-Oh", "Mistake", or "Deck Lockdown", slows down the archetype significantly, as the archetype requires significant searching to make combo plays and maintain their grind game