Okay, gonna say this right now.
This article is so full of spoilers you'll think you're in a movie with Paul Walker and Vin Diesel. The Argent Coliseum will be so spoiled that its parents bought it a car before it could drive. There will be less mystery to the Argent Coliseum than in M. Night Shyamalan's "The Village."
There. So. Thanks to Boubouille of MMO-Champion's help, I've spent the past few days digging through the spell and NPC data in patch 3.2's current PTR game files, slogging through thousands of new entries to find out how exactly the new encounters in the Argent Coliseum will be like (and who they'll be!). Well, I've been mostly successful in that regard, and I'm prepared to spoil about 90% of the Coliseum's encounters for you. But that's not all! This latest PTR patch was also kind enough to provide me with a ton of sound files related to the Coliseum and its set of instances, which has given me a very firm insight into what happens around the encounters. This particular article will focus on the 5-man instance.
Basic caveats apply: The encounters could change at any time, datamining isn't an exact science, I could be misinterpreting files, etc, etc. But I'm pretty solid on what I've written down, and anything I'm speculating on will be noted as such.
Any spell or ability listed in this guide will likely be a random rank, given the spell database's knack for throwing me 10-man and 25-man spells in the same area! Don't assume that the damage values are accurate for your favored raid size!
Remember, BIG SPOILERS AFTER THE JUMP. But if you can't contain yourself, then go right ahead, dear readers. Let's go down the rabbit hole.