Briar, The Witch of Regret

Flying
When Briar enters, each player exiles the top X cards of their library, where X is the amount of mana spent to cast Briar. Whenever Briar attacks, you may cast an instant or sorcery spell from among cards exiled with Briar without paying its mana cost.

" I was born amidst the Dark. Long ago, in the depths of the Abyss, my Father perished. The Dark shattered into tiny pieces, one of which was me. How frightened I was. A frail thing, born from but a splinter of Dark. I felt that I might