I distinctly remember, in the Anime anyway, a scene where Eva Unit 02 sorties to fight an Angel without Central Dogma's authorization (If I find the scene online, I will link it here), seen when EVA Unit 01 descends back into Central Dogma for reasons I can't remember (damage, maybe?).
Seeing that EVA Unit 02 has the soul, at least the maternal part of Asuka's mother, imbued into the EVA itself, piloting the mech would be impossible for everyone except Asuka, going on the basis of EVA Unit 01's connection with Shinji.
My question is this, if EVA Unit 02 has a soul that is only known to work with Asuka, how did Mari manage to pilot EVA Unit 02 without any known difficulties?