TL;DR The reaction buffs are too weak to not choose your stronger characters over, and should have been far stronger from the get-go than they currently are.

Among the many "EN can't read" posts and comments I've seen over the past few days on how people are dumb for not choosing characters that fit the recommend reaction, I'd like to instead look at the opposite end and discuss how bad the event can still feel to play if you *do* pick appropriately, if not make the experience worse overall.

As far as I can tell, the only 'reward' you get for filling the reaction bar is the temporary spawning of three orbs on the field, and picking one up makes the next normal attack deal a fixed white number shown as shown in the included screenshot, though the actual damage seems to vary for different reactions when looking at some different gameplay videos (this was Electro-charged).

And as big as that number may seem on its face... the health values of the enemies are so bloated compared to non-coop gameplay that the actual damage is often mere fractions of any elite or boss's hp bar, also shown above, making it a questionable choice if you want to pick a 'weaker' character to abide by the reaction when a stronger but unrelated character may well perform better overall.

Additionally, reactions do not seem to be tied to the stages themselves, leading to cases where you're actively sabotaging yourself for playing an element or reaction that is a poor fit for the stage you have to play.

I actually laughed when I got Electro-Charged with Coppelius as the boss, only to have our hydro players unable to even dent the cryo shield unless you picked Furina. I'm sure you've had similar such experiences that I wonder why the devs did not think of this ahead of time.

For the current co-op event... are the stage reactions really even worth paying attention too?