[@The Odeoron]The one who is trying to make deal with C'thon is Diavolo's son, Diego Volo, which technically makes Diego the step brother to Cyrus since Cyrus married Kyo-Kyo, who is Diego's sister. 

One thing to point out is that Diego absorbed Diavolos decaying body because of a power obsession that he [i]shared[/i] with his father, but he couldn't absorb all of it because part of it is in Echo, because plot that makes things more confusing.

So Diego, being the power obsesser that he is, began to hunt down Echo in the form of Lymbo because of more plot that will be preserved for later in a plastic container.

Anyways, Echo left his reality before Diego did, which I should point out is [i]not[/i] the same reality of this Cyrus, and Diego of course had to follow into the rift, but they ended up in separate places.

Another thing I should mention is what Manifests Diego has.
Those being: Time Control and Shapeshifting.
Yeah, he got lucky, really lucky...


There are a lot of things that are probably confusing, but I should say, this is still a work in progress.