I think reception for Erdrick is basically going to come down to two sayings, at least in terms of casual player reaction:
1. The people that will respond "Literally who?"
2. The memey people that say "Goku got in Smash guys!"
I think reception will be mixed at first, but eventually most people will quickly warm up to him through other means:
1. Passionate Western fans explaining the significance of DQ in Smash.
2. The likely booming positive reaction that will happen with Japanese fans.
I think those two factors will make Westerners look at Erdrick in a different, but positive light in a matter of days.
The scenario that reception for Erdrick would become as toxic as Corrin's is an unlikely one IMO.
Alright, things have changed slightly...
...P5R is 99.999% real. I'll be damned if that .0001 is the reality. Things just got spicy on my end.
Knowing that a Persona 5 port is likely coming makes me happy. Personally though, I wish they revealed a port sooner.
I was hoping for a P5 Switch port reveal more than a Smash reveal when the Game Awards trailer came.