It is impossible to get past ninja exam level 70. The toad has bull* cheating Immune State. It does too much damage, can't be comboed, can't be cced. Interuption doesn't work because the only chars I have either die turn 1 against the toad because they have the lowest hp (Neji and Guy) despite my having two healers, or because the toad cannot be interupted until it starts charging to use the water bomb. But once it starts charging the water bomb Neji and Guy do not use their interupt until the water bomb goes off, at which point they are already dead. If I start their mystery before the toad uses water bomb then they use their interupt before the toad starts charging and they don't interupt. This is all a result of the moronic decision to create a cheat for NPCs called Immune State that makes them immune to CCs. Had there not be a * Immune State then I'd be able to prevent the toad from using its OP water bomb.
Conversely if the Water Bomb didn't do OP damage I'd be able to survive and kill it.
As currently implemented, Water bomb is non interuptible, non stoppable via CC and non surviveable. Either the Immune State needs to be removed from the game altogether or all npcs with immune state need to have their damage severely reduced.