First of All I want to congratulate you for becoming a fire mage you are now stronger.Here are my recommendations.
30-33:Stay at ant tunnel it is still good EXP for you and you can most time one hit KO most of the time. Go stay at horned mushrooms or go to undead mushroom and that is good because they drop the chaos robe you will need.
33-36:Go to Ice Sentinials in Orbis tower they will be might eazy.
36-43:Jr Grupins Garden Of Green, Good EXP for You, they will be good but I must warn you they might be crowded at time you can power lvl there with your friends each covering a platform.
43-50:Jr Pepe at Orbis Tower floor one thats much easier for you then Snowy field to el nath because even if you dont have snow shoes ur still fine.
50-55:Jr Yetis this is the turning point of you they are QUICK EXP and they drop PERFECT but be warned they might give you a transformed Yeti which is far stronger but as a mage you still should be able to kill it.
55-60:wut to say REAL grupins real big ones u still should 2 hit KO them and they still easy to kill by then.
60-70:What is more to say almost anything in el nath you can kill they all ice and your fire.
Lvl 70+: El nath is perfect for you Lycanthrope everything you should be perfect then.