Hellbound Spoilers - Ritunn Outcast
Thalia eat your heart out. Cycling, flashback, transform, normal spells and abilities... Make everything cost more!
This is 100% a hatebear designed for multiple formats, and kept just fair by making it WW instead of 1W. Double white is very hard to play in Legacy (see Council's Judgment for a good example) which keeps this from badly damaging the meta.
There are definitely some far-reaching implications with this, though. It makes Stoneforge Mystic cost 2W for both halves. Snapcaster costs an extra 2 to get that spell out of your graveyard. Young Pyromancer costs 3 and all its tokens cost more. It even makes planeswalker loyalty abilities cost mana, shutting down superfriends and hurting control even harder.
In the end, though, it's just a 2/1, and thus very easy to kill. It's definitely one to be afraid of, though!