Permafrost Trap (4)
If an opponent had a green creature enter the battlefield under their control this turn, you may pay rather than pay this spell's mana cost.
Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.
If an opponent cast three or more spells this turn, you may pay rather than pay this spell's mana cost.
Exile any number of target spells.
Trap could always trigger if your opponent cast three or more cards in one turn. It could be the anti-hand dump mechanic.
Here is an example card:
Drain - U - 8 mana
Each card in your opponent's hand is fully drained of its mana.
It would also have a symbol for trap which means this card will automatically cast once your opponent casts his/her third card in a single turn. Kiora is casting a bunch of gem converters and getting ready to dump her hand and go into a loop? Nope. She casts three and then loses all that excess mana after her third card is cast.
Another example:
Aura Mutation - WG - 5 mana - Trap evergreen
Destroy an opponent's Enchantment support. Create X 1/1 green Saproling creature tokens, where X is that enchantment's converted mana cost.
This is the type of card I was originally thinking about when I came up with this idea. Instant cast support destruction that doesn't rely on creatures attacking. There are Omniscience decks and Imminent Doom decks out there that will combo off and kill you before you could even use a Flash support destruction to save yourself. In this case you could shut down the combo if you had this card in hand and it had full mana.
Here is my ultimate Omni/ID trump card:
Deconstruct - G - 5 mana - Trap evergreen
ZW2007- said: Do the devs, or really anyone for that matter, even look at this subforum?