Tai Chi is a set of movement base on the theory of circular motion, what imporant is the breathing behind it. I am not sure what you are referring to FOCUS ON POWER, but if you are looking for an art that deals with raw muscular power in the sector of Chinese art, you are looking at mostly southern style stuff like Ba Chi, Mantis, Hung's Boxing, Southern Boxing, The Eighteen Buddah etc....
Jiu Jitsu is the parent art of Judo, removing the lethal ingredient of Jiu Jitsu (striking technique, joint technique etc), you will have Judo:
Jujutsu - Wikipedia, the free encyclopedia
Depending on where you are from and who you talk to, it can be Jiu-Jitsu or Ju-Jitsu