So I'm making a campaign based around the Mystery Dungeon series of games and for that I'm making a template. Lore wise, they're weaker mimics of actual creatures created in the dungeons. I just wanted to know how much the CR is lowered and if I should do anything to it.
Name: Dungeonkin/dungeonspawn/twisted copy/whatever I decide to name this thing.
Alignment: Chaotic Evil
Type: The creature's type changes to aberration. Do not recalculate HD, BAB, or saves.
Ability Scores: A [NAME PENDING] gains a -2 penalty to all ability scores. This cannot bring an ability score down to below 1.
Skills: A [NAME PENDING] with racial HD has skill points per racial HD equal to 4 + Int mod. Racial class skills are unchanged, and class level skill ranks are unaffected.
Senses: A [NAME PENDING] gains 60 feet of darkvision. This does not stack with any darkvison the base creature already has.
Well, the augmented template adds +4 to all stats and is basically a +1 CR mod.
I'd say yours is a weaker inversion so would be a '+0' or at 'best' a -1.