Um about E-mouse, I thought he was going to be a comical character and do that sign holding thing but not actually be fightable anywhere, except maybe with a last word.
I had an idea last night when I was trying to fall asleep playing off this a little bit. I've got no clue how feasible it'd be to implement but my guess is either "not feasible at all" or "actually really easy once we've got the Embodiment system implemented at all".
Perhaps any time an Embodiment is created, have a slim* chance of it being E-mouse regardless of stage. E-mouse just stands around and holds the sign and doesn't shoot danmaku, but otherwise behaves like any other Embodiment (i.e. with regard to drops and such).
(* My intention is low enough that you can't
rely on being likely to get the benefit of the easy/joke Embodiment even so much as once per playthrough, but not so rare that a relatively casual player is unlikely to come across it ever. My initial gut feeling is something like a 0.5-1% chance each time an Embodiment is summoned in the main game, possibly higher in EX and OMES since they don't
have up to 28 Embodiments per playthrough.)
This may be a horrible horrible idea regardless of implementation feasibility and I give you all free rein to shoot me for it. Just figured I'd get it out there anyway while it was on my mind.