Is to disengage, heal (ideally using preps so that me muter isn't also healing) whittle the muter down, and catch them by surprise by switching to offense when they are gushing.

Also keep wimpy high so that if it gives you the mini freeze, you can still exit the fight. Otherwise the risk is that you get frozen just for the moment you could otherwise type flee.

Not every class can do this, since a dexy muter has great melee too.

I found when I've played muters and fought them that mental jolt is too strong for the level it's received at.