Short n to the point..
Level 15 Mage (a lot of people disagree with me) - however in the beginning it was where I started out so I've got to inclood it.
Level 18 Nuke Bird - Extremely fun, no better level to learn ranges of bird without getting rushed just because you're bad (although if you wear nooby vanities unfortunately you increase the rate at which you'll be pile on by the opposing team).
Level 20 Tank Mage - Just for security at this level range, many noobs imo underestimate the value of having 1 powerful char, by doing this then you can force people to off you.. Or at least some of them.
Level 27 Fbow nuke mage or Toy nuke. - EXTREMELY fun level range to play without being constantly trashed by people. However does require prior knowledge of kiting & nuke comboes & ms timings (its actually possible to beat 35 pin mages).
Level 30 Mage - I'd do this last, I struggled immensely even with gear & build in the beginning just because of how different it was.
Level 32 Warbird - Pure Nostalgia.
Level 35 Mage - Very fun, made some good friends here - relatively low cost to be one of the best ( or the chance to be).
Level 40 Bear - Hell... I wish somebody had told me about this level earlier. High cost for none plat pack, low cost for plat pack - obv reaper bear is way more fun.
Level 45 //// could never get into this level mainly to the fact I didnt have room to breath as if you're unknown you'd be dropped in record timing of joining a game.
---Never liked 51-61 mainly due to the pvpers there seemed rather arrogant & I dont think I ever found somebody with over 10k kills on 1 char but like a collection of 50k kills spread over 10 chars..
Level 66 Warbird - Highly underestimated & surprisingly fun.
Level 66 Mage - Just for the nuke fights.
Level 77 Bird - Definitely most fun char at endgame (in my opinion) Not too overpowered/underpowered. Possible to beat the best with minimal gear but maximum effort + good ping.
Level 78 Dev - Just Hax.
Bookmarks