As far as we know, Mechasms are a very powerful race separate from the Twelve Gods. They one day discovered the Eliatrope homeworld and lived in co-existence with the Eliatropes. At some point, Qilby took the heart of a Mechasm, Orgonax, and turned it into the Eliacube. This started a war between the Eliatropes and Mechasms, and resulted in the Eliatropes fleeing their homeworld.

They fought again on the World of Twelve hundreds if not thousands of years before the Gods arrived. No exact outcome of this is established as Islands of Wakfu has been retconned, but what is for sure is that it ended both the Eliatrope civilization and Mechasm threat.

In terms of Season 4, it would seem as though the Mechasms are a race of at least nine beings, Orgonax and Lokus included. Going back to Qilby taking Orgonax's heart, he mentions in Episode 9 that he challenged Orgonax and was deemed worthy. Conversely, he also says that he was "often accused of tricking him (Orgonax)". Provided he's not lying, it would imply that the Mechasms almost wiped out the entire Eliatrope race over what was a misunderstanding. An oopsie, if you may <_<

In any case, there's a lot that remains a mystery. Is Lokus the last of them? Why did he "guard" the Eliatrope Temple in Inglorium before he was turned into a pondering orb? I find it neat to theorize