Two bosses will enter... but only one will get to leave! Every week at WoW Insider, we pit two of the most interesting bosses in the World of Warcraft against one another in a fantasy deathmatch -- in the end to emerge with a single boss of bosses, victorious above all others. And the best part? You get to tell us who walks away the winner and who doesn't get to leave our arena at all. Today we're considering a fight between the Black Temple's Teron Gorefiend and Gruul the Dragonkiller. Curious as to what might happen if these two met up? Keep reading and we'll discuss what each of these bosses can do and what might happen if they met up.
Teron is a difficult fight, to say the least. He deals heavy melee, shadow, and fire damage and requires coordination and strategy to defeat. Beyond basic melee attacks, Teron will do the following:

Shadow of Death: Turns the target into a ghost and spawns 4 Shadowy Constructs. However, for the purposes of our fight, we will assume Gruul is immune to such instant-kill abilities.
Doom Blossom: Spawn and fire Shadowbolts at Teron's enemies. These last about two minutes and keep spawning as the fight continues.

Crushing Shadows: Teron will randomly debuff one of his targets with Crushing Shadows, which increases Shadow damage taken for 15 seconds.
Incinerate: A high damage fire-based DoT.
Gruul relies primarily on melee damage to bring down his enemies -- and that damage only gets worse as you fight him, for every 30 seconds, Gruul will buff himself with Growth and increase his damage by 15%. We're ignoring abilities that relate to the specific terrain of Gruul's lair, because we presume these fights take place in a neutral arena. However, Gruul still has a few tricks up his sleeve:

Hurtful Strike hits the 2nd target on the threat list for a high amount of melee damage (12k to 13k). If there isn't a second target in melee range, Gruul will hit his primary target with Hurtful Strike. The damage increases with each Growth.
Ground Slam: An AoE knockback.
Gronn Lord's Grasp: After being knocked back by Ground Slam, players receive this debuff, which reduces movement speed by 20%. Stacks.

Stoned: After 5 stacks of Gronn Lord's Grasp, the player will become stunned by Stoned.
Shatter: After Stoning his targets, Gruul will Shatter them, dealing damage (more if players are close to one another.)
So who do you think will win and who do you think will lose? It's nearly time to cast your vote, but before you do, remember: we're considering these two bosses at approximately the same health and strength. These fights are all theorycraft, considering each bosses' abilities -- they aren't a math equation where we consider exact hitpoints.