I don’t personally think Oathkeeper is the way to go. Here is link from Adoomgod Sorc [1.1.4.0] Xiuhtecuhtli the God of Fire AAR [c+][sr75+] - Sorcerer
To level with AAR you need to have enough energy sustain , cause AAR is mana hungry skill. Interesting idea is to go with Olexra flash freeze+fire spell in combination.