When the effect of an Spell, Trap or Effect Monster is activated, you can return 1 face-up "Mist Valley" monster you control to its owner's hand and negate the effect of the card and destroy it
The typical used copy of Dark Charizard is worth quite a bit less though, with most selling for somewhere in the region of $220
Flipped, Adanto, the First Fort makes a 1/1 with lifelink for 3 mana
Ensure the sacrifice effect every turn by sacrificing the Shaman to himself each time and you should be golden
This really is just an absurdly powerful payoff and the best face card out of all of the four decks
Eventually, you can cast Retract to rebuy all your Artifacts, draw tons of extra cards, and cast Grapeshot for the win