Though according to the Ovelord Wiki, even Greater Doppelgangers could only mimic abilities to 90% effifiency at level 60, and there seems to be a drop-off in potency, since Pandora's Actor (who is at level 100) can only copy abilities at 80% efficacy.

Also, wouldn't Chuunitrixx need someone who knew all those abilities and skills to copy? I didn't find anyhting on the Wiki that states that Doppelgangers have natural spellcaster levels, nor that they can store multiple different peoples/creatures abilities for later use - unlike something like a Redeem Slime.

Again though, this might just be because the wiki is lacking in information. There're a lot of stub and unfinished articles on it after all. >_>
Lazy-ass Maruyama, not spending all his time fleshing out details about stuff...

On a different note;

Why're you guys not carrying Rodias off? Pick up the couch he's on and get outta there! Yandere-snake-girl gonna kill him! D: