The legacy quest trilogy. Book 3 - Steve Lyons

Magneto - the X-Men's arch enemy and mankind's greatest foe, has dramtically raised the stakes in the life and death struggle to find a cure for the mutant-killing Legacy Virus. Magneto has created a vast arsenal of Legacy Virus bombs that he's having his cohorts plant around the world. When he detonates the bombs, all of humanity will be quickly infected and soon die unless they receive the cure, a cure that only he has!
The X-Men must stop Magneto before he can activate his insane plan. But with Magneto the acknowledged legitimate ruler of the island nation Genosha, stopping him will not only be difficult...it may be impossible! Meanswhile, Sebastian Shaw, the Black King of of the Hellfire Club and an embittered, now cast-aside pawn in Magneto's mad scheme, is forming a terrible plan of revenge.