Liliana of the Veil, Nissa, Vital Force, and Chandra, Torch of Defiance are all planeswalkers that I've played in midrange builds that ended up allowing me to steal games from UW Control
The idea is to have Yidris hit, then go crazy and start casting spells for free, thanks to the cascade ability
That plan may involve taking fast Prize cards with a powerful Pokmon ex, setting up a Stage 2 attacker that can take repeated knockouts, spreading damage across the opponents board, denying Energy, disrupting the opponents hand, or trading efficiently with smaller Pokmon
Ive been working on it on and off for about 3 months now, tweaking it to be as competitive as possible on a somewhat low budget
1 Wand of Orcus
They were never meant to enter public circulation