She is played in the sideboard of Vizier Knightfall sometimes. Planeswalkers attack a unique angle that midrange decks trying to go 1-for-1 with removal have a hard time with. When that deck makes infinite mana she also becomes pretty insane outside of hard removal. She was in a few Bant Eldrazi sideboards for a while but other walkers are argubly better. Those are the only places I can think of that she is/was played.
MTGO/MTGA: Tyclone
My Primers ~ GWx Vizier Company ~ Knightfall ~ RG Eldrazi ~ Green's Sun's Zenith
More Brews ~ Modern Four Horsemen ~ Gitrog Dredge