If an effect has given Infesting Radroach -4/-0 so that it's a -2/2 creature, doubling its power gives it -2/-0, and it becomes a -4/2 creature
There are so many applications for this type of ability because black has so many ways to benefit from having cards in your graveyard
1 Suspicious Bookcase
You'll have to pay the mana cost of any spells cast later in the turn, even if you cast fewer than three as you resolved this ability
Im a big advocate of the build-your-own haymaker approach, and Kembas Banner can do that
not legal for sanctioned play (SLD #2443) 10 Non-foil double-sided tokens TBA tokens with new art (SLD #TBA-TBA) A life wheel Updated cards New art Grand Crescendo Song of the Worldsoul Soul Warden Break Down Cultivate Finale of Devastation Bountiful Promenade Plains Forest Skinned cards Miku, Song of the People (Trostani, Selesnya's Voice) Archangel of Tunes (Archangel of Thune) Cascade of Song (Halo Fountain) Miku, Voice over All (Shalai, Voice of Plenty) Miku, the Complete Performer (Vorinclex, Voice of Hunger) Deck list A deck, themed around life gain and go wide creature tokens