Mister Sinister got his wish fulfilled by the Scarlet Witch as everybody else in the House of M.
He was transformed into a seemingly simple man living on a farm. He raised Cable (House of M) who from an unknown reason in the House of M reality was transformed into a infant.
But as Deadpool entered this reality, Sinister’s evil side started to show. After inviting Deadpool, Siryn (House of M) and Cannonball (House of M) to a barbeque he revealed he laced the food with drugs so that his “guests” would be easier to study. However, since Deadpool was the only one who ate, his healing factor made him virtually immune to the drugs. Sinister then took them to his laboratory in the basement. Subsequently Mister Sinister’s real plan started to unfold: he wanted to use Cable who would become the savior of the world for his one evil plans.
Deadpool started a fight with Sinister for baby Cable’s future. Deadpool eventually bodyslided with Cable to his own reality and then the world burned to white once again, thus the House of M disappeared.