While red and black have tons of good cheap removal, Path to Exile is somewhat of an outlier for white, a color with versatile but often more expensive options
All three of my black choices happen to be four mana midrange bombs, so this has a lot of competition, but the sheer amount of stats on this thing scream playability to me
And now
Sure, you can get more power from the bigger cards but if you can't get there as easily it isn't worth it when you are winning with the cheaper stuff
They are Vrondiss, Rage of Ancients (a Dragonborn Barbarian, leading the red/green Draconic Rage deck), Prosper, Tome-Bound (a Tiefling Warlock, helming the red/black Planar Portal deck), Sefris of the Hidden Ways (a Genasi Wizard, leading the White/Blue/Black Dungeons of Death deck), and, finally, Galea, Kindler of Hope (a Half-Elf Paladin, topping the White/Blue/Green Aura of Courage deck)
I think the only places you would see this getting used now is due to the cycling and as cyclers go this is one of the weaker ones