One Man's Trash is another Man's Profit #1 (By Debris)

The cheap cards I'm looking at today are Snake Rain, Elegant Egotist, and Dark Calling
Snake Rain
Normal Spell Card
Discard 1 card. Select 4 Reptile-Type monsters from your Deck and send them to the Graveyard.

Eew, Reptiles? No, don't be ignorant. As a whole TYPE, it's crazy to assume they won't either get a good archtype to themselves or just more support later. 4 Foolish Burials at once is actually pretty broken, even more once you realize you can run 3. Right now this card is only a deck thinner or an instant Dark Armed Dragon, but with future monsters and Offering to the Snake Deity, this card has a lot of potential.

Elegant Egotist
Normal Spell Card
You can only activate this card when there are 1 or more face-up "Harpie Lady" on the field. Special Summon 1 "Harpie Lady" or "Harpie Lady Sisters" from your hand or your Deck.

Konami has hinted multiple times that Harpies will be getting more support, and right now, this card is one of the best Harpie cards available. It's an instant summoning or any other Harpie in your deck, which is amazing however you look at it. Also, if Harpies DO get support, it would likely be as another monster that is treated as Lady or Lady Sisters from the deck.

Dark Calling
Normal Spell Card
Remove from play, from your hand or your Graveyard, the Fusion Material Monsters listed on a Fusion Monster Card that can only be summoned with "Dark Fusion", and Special Summon that monster from your Fusion Deck. (This Special Summon is treated as a Fusion Summon with "Dark Fusion".)

This card is Miracle Fusion for Evil HERO Dark Gaia. That's pretty big right there, especially as we get more and more good Fiend and Rock monsters. Dark Gaia OTKs have a load of potential, and it will just take time and more cards for the deck to be broken.