With the death of Y'Shaarj the sha came. I think if C'thun was really dead, we would have noticed it somehow.
"Arygos theorizes that the element which is born of conflicts between the Old Gods and their minions is also extremely deadly to them under the right conditions"
http://www.wowpedia.org/Quest:Imperial_Qiraji_Regalia
"Combined with the element created from the volatility of their own God, they will become a force of reckoning. "
http://www.wowpedia.org/Quest:Imperial_Qiraji_Armaments
Combining these 2 statements strongly implies that C'thun was involved in the creation of Elementium (since he's an Old God) but not that it's his own blood.
Old Gods are certainly not immortal. It may have been hinted something in this way in the past, but certainly not anymore. We know Y'shaarj is dead, and we know by a interview with the devs that the Titans actually killed a lot of Old Gods (probably in other planets).
So, C'thun can most certainly be killed.
That said, we also know that killing an Olg God here in Azeroth brings trouble, as killing Y'shaarj brought forth the Sha.
So, I imagine that if C'thun had indeed been killed by us, it would have brought a similar effect. Since nothing of the sort happened, I believe C'thun is still alive in some way.
Maybe we just destroyed his physical form, and his spirit lives on. Maybe we just banished him, meaning we didn't really kill him.
Or maybe... it is just a hiccup by the devs, and he indeed died, but the devs simply forgot to bring the correspondent Sha from his corpse. Which would be lame....
Was it not stated that the Old Gods were basically intertwined with Azeroth ? Yogg-Saron was supposedly so massive that he encompassed most of Northrend. If this is true we basically just killed his left nut.
They can't die or Azeroth will be destroyed
Originally Posted by kasath
it was stated in an interview that the only old gods that are really dead were the ones killed by the titans it was also said that the titans killed lots of old gods both here and on azeroth and that eventually they found out that killing them did bad things to whatever orld they connected themselves to.
killing ya'shaarj created the sha. who knows what the other ones did. so if yogg and c'thun were dead there would be somekind of side effect we wouldve seen by now. also its heavily implied both in places in northrend for yogg and the comic ifor cthun that all we really did was kind of "reapply" the lock and beat them down to the point that they now have to recharge basically
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We never killed C'thun, we pissed off one of his many eyes
Pretty sure they kinda just go inactive once we defeat them then a long regeneration period takes place.
We know Old Gods can be killed and Knaak's crap about them bringing Sargeras to his knees yadda yadda in the Sundering is just as half-assed and ridiculous as a time travelling orc being venerated as a hero of the Kal'dorei 10000 years before Orcs screamed into Ashenvale, seemingly forgotten in the immortal mind of Tyrande.
Y'shaaj, old god, Y'shaarj slain. Ra-den and the Mogu brought him and his mantid army down and Ra-den isn't even a Titan but power on par with the Keepers of Ulduar. Certainly no Pantheon member. But the spirit or what have you of Old Gods (like the Sha) can continue to be a malevolent force and they aren't removed without destroying the world and re-originating it. It's not so much a question of whether Yogg and C'thun are dead but rather what kind of malevolent force was released by their deaths, just like the death of Y'shaarj.
100% incorrect
"The Titans slew Y'shaarj, but with his dying breath he cursed Pandaria by infesting it with "shadows of his former self". http://www.wowwiki.com/Y'ShaarjSource
Because he did doesn't mean everyone did, the old gods being invincible and immortal doesn't make sense because it would punch holes as big as earth into the lore. How were the Titans able to beat so many of them in the first place, they did they overcome those on Azeroth and managed to kill some and imprison others when they are so extremly far stronger?
It's the lore being changed around a lot to suite whatever needs they have at that moment. They go from merely parasites on Azeroth to invincible abominations from beyond the veil to something in between to something completly different in every single book they're mentioned in. That some of these changes don't fit the lore so far doesn't seem to bother you guys.
I would say they are like weeds, you can kill the top but unless you kill the roots they will just pop back up..it's just that their roots/ tentacles are so deep in azeroth that if you pulled the roots out the world would break..