Lightning is a lethal hazard. It can kill instantly. However, I like the idea of more of these non fatal hazards.
here are some threads of mine which show some weather effect ideas.
WEATHER and its effects in MKD
NEW Stage Concept - The Temple of the Elements
There is a third thread I wrote on Stage and Environmental Hazards, but I cannot obtain a link due to the forum search being down.

I've posted in both of those. The lightning was just an example of something that could happen if you're in the wrong place, like the Acid Buddahs.
How about health bonuses or temp regen, 2x strength, blocking takes no damage, speed upor even koins hidden in the arena. I dunno, just thinking too hard I guess.
Ka-Tra