You think it would have been awesome if the "Algalon" boss for ICC were three "ancients"?. (I'm late I know )
Once you defeat Putricide(Heroic), Lanathel(Heroic), Sindragosa(Heroic) and the Lich King( Normal/Heroic( better loot)) the giant ice pillar in Marrowgars room breaks open relieving a tunnel you travel through. Pretty long tunnel mind you. After running for over 2 minutes you drop in this well, into the water. You get out and you see this giant coliseum and 3 three statues in fighting positions. Between them in a book you have to read to activate the encounter. Some one clicks on said book and there is this sorta creepy dialogue along the lines of
"We three statues of the Nether realm are the warriors of old. Betrayed by our master to pursue ill-gotten gain.(Demonic laugh) I see he is dead, with this Bolvar Fordragon taking the throne. (More demonic tone) Why has he not released us from this torment! Soldiers of the Alliance/Horde, you have fought valiantly to secure peace. However, you are stuck here with the only way out is through our defeat. We want to be free. If you ever want to make it out alive, you must first defeat us!"
At this point they "thaw" and start attacking players. One ancient has no threat table and hits moderately with DoT's and roots/snares. One ancient does have a threat table but hits like a mach truck( on one target, no need for stacking). The other has an ability to a 10 second whirlwind doing 10% damage to hp per second to anyone in it's area regardless of armor and health. Total amount of health from each mob is 45million, no enrage timer.
As you can see if you have played other blizzard games you'll know where I got the idea from :P. I also could've gone into more detail but it would've been a wall of text.