I could use this build in pre-alpha to beat 25+++ without much trouble, but now from nm3 and so on, this combination is getting weak. Maybe there is nothing wrong with flameburst or boost aura, its the difficulty scale issue. But still, this build is not as good as elemental traps+frost tower. And also, the uber sphere for flameburst is not as useful as others like elemental chaos, i would rather choose 2 elemental chaos instead of spending 40 du on a mid range tower which is hardly to be boosted by frost tower. (There is a huge dps gap between frost tower boost and boost aura. Most important