the whole plan is still flawed. even if he manages to save the emperor's life, all he has done is kick the succession down the road. no indication has been made of the empower being immortal so eventually he will still die and Rui will still have to ascend.
Massa is a useless trainer with absolutely zero integrity. the only correct thing would be for him to receive some special "training" involving a rack, stocks, and a cat'o'nine tails