Mischievious [sic] (yes, it's misspelled in the game) Naberius is a tough, giant, level 57 unique mechon monster roaming behind Gate 3 within Sword Valley. While it's typically safe to be a few levels below most unique monsters, in this case I would recommend being at LEAST level 57 if not higher to make things easier for yourself, since Naberius' number of area of effect attacks can make things difficult, especially in the very beginning. (Sharla and Shulk died several times to his initial flame thrower attack.)
Mischievious Naberius isn't required for anything (that I know of,) it's just a challenging battle that I thought I would attempt and record. Also, for those of you that haven't gotten very far in the game - that glowing blade Dunban is wielding is not the Monado, just an anti-mechon weapon that's available for purchase after Galahad Fortress.
