He and antiman are the most valuable characters to use a mrut on since their bios cost hard cash. However like someone mentioned, they are outdated and there are other stronger characters than them now. I would say just stash it and wait although that takes very strong self-control lol
There’s nobody else worth using a MT2 ticket on. The big benefit of it is skipping the ~550 bios otherwise needed and all other characters have other means of getting those bios. Only the Ultimates have no good means of getting bios.