What affects the arena battle, lower power can win?

The most influential is the element used, even with the right element to counter the opponent's element in the arena, even if we are 6k lower, you can still win.

But that's not the only factor, I realized when my power was 57k earth element, against 61k earth element, and I won.

Another factor to consider is.

1. additional skill quality and level from tower

2.Dragon, Dragon level, skill quality and portrait quality (dragon or immortal)

3. Immortal skill, for example, the opponent is Zenobia. Genghis Khan, Good for countering Zenobia's skill which has HP Regen

4.Troop positions

5.Immortal quality (level and number of stars, etc.)