I think ^^^ is playing with fire. A bunch of river cards really suxors here and we have to shut down to aggression. If we call, we may get an additional $36 from MP, but if the river blanks we lose all value from the donk's FD. We also probably lose value from MP's overpair, because he can't call a river bet unless we give him super odds.
I raise and get value from the donk. Forget MP the TAG.