You could try blinding him before you take out the two ipoohs, and if all your attempts and blind fail, close the app and restart and you will have all your abilities back. This will allow you to go into the round fresh every time until you get a good start with blind stuck.
You can't touch him at all until you've beaten the two Ipoohs, unfortunately.
You start that battle only, for example if you use it on 4/4 (the boss stage) you start from the boss battle again, from 4/4 with the random bonuses.
Edit: you start with all the abilities charged, and any effect removed.
I used one because the helicopter killed my Rydia on his first turn ¬¬.
Out of interest do you know if you can then exit app and start it again and have those buffs in place?
Anyway, after around 5 hours on and off of trying I finally did it! Just two more elite dungeons to go!