Test of Metal [A Planeswalker Novel] by Matthew Stover

From the ashes of defeat, the planeswalker Tezzeret will rise again.  Beaten to within an inch of his life and left for dead by the psychic sorcerer Jace Beleren, Tezzeret has lost control of the Infinite Consortium—an interplanar cabal he built from the ground up to achieve the sort of power and influence few in the Multiverse have ever achieved. Now he must turn to a former enemy for help: the dragon Nicol Bolas, perhaps the only being in the Multiverse powerful enough to get him back on his feet.

Agents of Artifice [A Planeswalker Novel] by Ari Marmell

Jace Beleren is a planeswalker who has taken the path of least resistance. He is gifted and powerful, but chooses not to push himself. Part of an inter-planar consortium that deals in magical artifacts, Jace has some power and influence. He also has a certain amount of security. That’s all about to change. When Liliana, a dark temptress with demons of her own (quite literally), comes into his life, she brings with her more possibilities, but also more problems.  Under attack from external interests, a friend dies because of decisions Jace made. Upset with himself and fearing for his life, Jace sets out to find who is behind this new threat. What he uncovers along the way, an inter-planar chase filled with peril, will alter everything he knows.