Hi there. During the FPE I came up with a funny build using the elementalist's area attacks and the assassin's teleporting abilities.
Skills could be as following:
Aftershock
Churning Earth
Sliver Armor
Glyph of Lesser Energy
Shadow of Haste
Death's Charge
Recall
Aura of Restauration
The tactic is simple and fun and it can maybe also be used in other PvP arenas, yet I only tried it in 12vs12, since you can do it all by yourself. If you try this build in any other arenas than Faction 12vs12 you should bring Ress Signet instead of Recall.
First, get yourself into a fine distance of the enemy, where you'll be safe after your charge to regen. Then, activate Aura of Restauration, since you'll need health once you jumped into the brawl. Now you need to be quick:
Activate Shadow of Haste and rush to a chokepoint of the enemy's team. When in range, cast Death's Charge at a foe in the middle of his team, now you should be right in-between their lines. Be sure to be quick now, since Shadow of Haste is still counting down. Immediately cast Sliver Armor which will deal additional damage to any foes that have already recognized you. Now use Glyph of Lesser Energy, followed by Churning Earth. Finally use Aftershock. If you timed it right, you'll be teleported into safety now, leaving crushed and hopefully dead enemies behind.
The choice of skills isn't perfect, since I wasn't too sure of base and Factions/Prophecies skills but the above-listed skills are available for Cantha characters. I think Shockwave is more effective and should replace Churning Earth or Aftershock, but I didn't have enough time to test the build. It was quite effective, especially against Assassins (
) and Monks. Warriors haven't seemed to be too impressed by my attacks :P
Not a perfect build, but none were from the scratch, but could be used for some kind of spiking with two or three people. Keep an eye for Ward Against Elements :P