Mai's power makes things real, so it de-nerfs weapons, heals people to the point of being able to bring them back from the dead, and when it and her issues are repressed, creates invisible demons to make her life suck and ruin everything she loves.
She can also tell from a glance if someone isn't a normal human and what they really are, but I chalk that up to just knowing a lot about how the supernatural works in her world, which is why she couldn't do it in AL because different worlds, different rules.
honestly except for regeneration the Doctor's powers are really ill-defined or sort of gamebreaky, so I just assume they're still nerfedQueenie's gonna be able to read him like an open book