I just finished reading the latest kickstarter update about PVP, and one of the sections mentioned arena matches. I was never a big PVPer, but I recently redownloaded an old favorite of mine. In the game Jade Empire, there was a portion of your main quest line that took you to the arena. It was traditional in the aspect that you fought tougher enemies each round, but one of my favorite features, and most frustrating, was a round that gave you a very short period of time before the next tier would join the battle. It looked something like - tier 1 match start, 20 seconds later, tier 2 enemy joins, 20 seconds later, tier 3 enemy joins, ect.. It was a very good challenge and you had to play your character with different tactics and as the enemies from different tiers piled in together, you had to keep on your toes. Fable also had a good design to their arena setup as im thinking about it.
Is something like this possible to be put in the game either as a story arc, or possibly a recurring event? I just thought it could really help people learn how to play their characters with different types of enemies simultaneously. It could also be team(non PVP) as well.
Just some more food for thought