They should put a time limit on battles with the a time end going to the team that inflcted the most points across the 3 areas

The unkillable champion has a "right" to take one more turn.  

I think an unkillable champ should get the next turn, irrespective of turn meter, if it takes a hit while it's the only member (or only living member) of its team.

This  happens  in  several  situations.    you  have  to  manual  the  battle  and  do  not  use  the  tm  reduction,  or  use  team  setup  to  disable  the  tm  skill.    With  alure  those  options  are  limited.  Another  strategy  is  to  strip  or  steal  the  unk.  Another  strategy  is  to  target  the  champ  with  unk  before  the  other  enemies  are  dead  so  you  have  other  targets  when  the  unk  is  up  so  that  the  champ  will  get  a  turn.    Otherwise  do  mot  use  alure  or  reduce  her  crit  rate  so  she  doesn't  apply  the  tm  reduction.  Otherwise  admit  that  this  is  not  a  winning  battle  for  you.  Its  not  a  bug.

My Fire Knight team has so much turn meter reduction (Lightsworn + Allure) that it's difficult--in some situations impossible--to manual an unkillable Gnarlhorn if it's the last enemy standing.

The Gnarlhorns have to be taken out first, which is easy enough if I'm watching (semi-little known fact: if you click on an enemy while auto-battling, your team will direct all its single-target attacks at that enemy).  

But I don't want to watch; I have a job!  I want to use Multi Battle.

Oh, and it's also annoying that Multi Battle can only be turned off by surrendering.

use a champ that ignores unkillable like rotos or take a buff strip champ.  rhazin can remove those unkillable buffs, and theres dozens of champs, even rares, that can remove or steal a buff.

There is a free champ that does it, farmable in campaign, and he did a ton of work for me into mid game and was a solid FW21 champ for me too.

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And, just to show he is useful late, here is my first FW21 completion for Banner Lords :D :D

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