Sure, I can try this. I rather like this arena, as the arena I used for my first battle with oslo, and i've added some modifications to it to make it more interesting.
Arena: Forest of Aromas
Due to the abundancy of plant-life, grass type moves are increased in power by 2 points of damage (added on after damage calculation).
This Serene neck of the woods is full of flowers of different sizes and shapes.
Among these flowers, there is one that gives off a soothing aroma that rejuvenates those that dwell in this place.
Every round, each pokemon battling gains 5% energy by sniffing the aroma of the minor flowers, and each have a 20% chance to sniff the aroma of the more powerful flowers of the forest, gaining 10% energy instead and being healed of one random status condition.
These flowers are very special, however.
If a fire type move is used, there is a high chance (up to ref, but probably ranging from 60-90%) for the forest to catch on fire. If this happens, the minor flowers start spitting out a defensive, acidic aroma that hurts each pokemon for 5% hp each turn; and the more powerful flowers have a 20% chance to affect the pokemon and hurt them for 10% hp. This effect lasts for 5 turns.
If a water type move is used, there is a high chance (same as the chance w/ fire) for the flowers to be strengthened by the water. The minor flowers will spit out a stronger aroma that will restore energy by 10% instead of 5, and the more powerful flowers will restore energy by 15% instead of 10 and heal each pokemon for 5 health. This effect lasts for 5 turns.
(might be adding more effects as I think about it)