The snowman enemy is immune to melee attacks, but it also lacks any melee attacks of their own. Their fireball missing is probably due to your Reflect status (cast Dispel Magic on yourselves and see if it still doesn't work). I don't know about their immunities against magic. I think they just don't take any damage from anything, ever. And they're immune to all SEs, except one (more on that later). And they run away after a while.
As Mr X mentioned, there's really only one way to damage them:
Also, would you be willing to take over my Grave Flare spell exchange, and make that into reality? (Speed Up <--> Fire Bouquet) The effects can remain the same (Grave Flare is <damage + Atk down>), for the non-Turbo people in Romhacking (they have no access to Inferno Barrier, so Primm's other Salamando spell would still be an attack spell). I'm having a rather tough time trying to change enemies to target the spells correctly, and I'm failing. I'm feeling rather frustrated with all my failures. I also completely failed to edit the spell graphic (I changed the animation pretty easily, but I can't change the colors without screwing up the animation). You can have all the credit, of course.
Vanilla My intent
Chess Knight Speed Up (Gnome, self) Grave Flare (Gnome, one-enemy)
Ghoul Speed Up (Gnome, self) Grave Flare (Gnome, all-enemies)
Imp Fire Bouquet (Salam, one-enemy) Speed Up (Salam, all-ally)
Spikey Tiger Fire Bouquet (Salam, enemy) Speed Up (Salam, self)
Mech Rider 1 Speed Up (Gnome, self) Speed Up (Salam, self)
Mech Rider 2 Speed Up (Gnome, self) Speed Up (Salam, self)
Mech Rider 3 Speed Up (Gnome, self) Grave Flare (Gnome, all-enemy) <-- He would attack OFTEN with this spell (due to AI trying to cast Speed Up on himself), making him quite challenging, in a good way.
I can give you my progress (name change, spell menu change (plus color), spell animation (minus color) change, and effect change), but I have a feeling that's really easy for you. The stuff I failed to do (spell color, enemies use the correct target) is probably the hard part... maybe. I also made Salamando's remaining attack spell, Fire Wall's PWR from 33 to 43 (don't want Salamando's attack spell to be weaker than Gnome's).
For the Dark Stalker in the Emperor's room, was there any reason you put only 1 Dark Stalker, instead of 3? If I remember correctly, there were 3 Dark Ninjas in that room.@Queue
Is there a way I can edit [Quick_Recovery]? While I like that they get up quickly, they're getting up WAY too quickly. Even with double stamina regen, enemies are getting up faster than that. I want to make them (and consequently PC) get up slightly slower (but obviously faster than vanilla). I looked at the codes, but I have absolutely no idea how to edit it.