The brains behind Magic: The Gathering ran a several month-long publicity stunt involving a conflict between two factions, the native Mirrans and the invasive Phyrexians. To the surprise of absolutely nobody, the unquestionably evil, parasitic, invasive side won and renamed the realm of Mirrodin into New Phyrexia.
And in the Shards of Alara block, the dragon planeswalkerNicol Bolas succeeds in bringing about the Conflux and merging the five shards of the plane. And immediately after that, in the Zendikar block, Bolas manages to get the Eldrazi released from their prison. And he was instrumental in bringing about the rise of Phyrexia as well.
In the most recent return for Bolas has him creating an army of zombies that have all their skill that they had when alive, select warriors gain new and powerful abilities, warping an entire plane of reality to suit his whims before destroying most of it and defeating the Gatewatch, who had just defeated two of the Eldrazi titans and sealed the final one into a moon, with insane ease and scattering them to the far corners of the multi-verse just to have a chance to survive.
How bad was it? Well, Nicol Bolas erases part of Jace's mind, nearly kills the indestructible Gideon, puts out Chandra's flame, turns nature itself against Nissa (who can command Nature with a thought) and easily overwhelms Lilian, the strongest Necromancer ever, with such ease you would think he was swatting flies.
Hell, Nicol Bolas pretty much wins every time he appears. The only significant loss was his death at the hands of Tetsuo Umezawa, and even then he returned from the dead and slaughtered the entire Umezawa line, so...
In Magician, part one ends like this with Janus achieving all his goals; taking Natasha, defeating Edermask and uniting the continent through conquest with him in the ultimate position of power.