I usually try to keep Frenzy Top because its his most powerful attack, on level 6 i would switch Thunderclaws for Majestic Roar since i feel that the extra aoe is kinda useless at this stage with the adds because you are rather going to want to focus on the opponent. Majestic Roar gives that extra slowing effect that fits it perfectly. This is my personal build feel free to use it. Works great for me cause its all about getting those kills faster without any problem of losing people adds shouldnt be a prio.