The Proof Of Israphel's True Identity! (Theory)
I know a lot of people assume Israphel to be the original Xephos from Yoglabs, but I really just wanted to put all the evidence I can think of in one place, so here it goes.
Yoglabs Xephos is obsessed with taking over the world, cloning people to follow him and machinery. Israphel's main goals are to clone people to follow him (e.g. Evil Honeydews), bring the sentinals online, and take over the world.
Israphel has had many opportunities to kill Xephos and Honeydew in SOI, and also had a great advantage to do so, but chooses not to. Instead he seems to provoke them and cause chaos around them instead of straight up killing them. This could be because he knows that they are linked to the cloning systems, and therefore knows that killing them is pointless, as he knows that they'll just respawn. And he knows this because he was the one who created the original cloning vats.
Israphel sends his cultists everywhere as minions. It's like he knows the heroes well enough to know that they'll get caught up everywhere they go. So Israphel sends his cultist everywhere to slow them down. Predicting everything. Because he made them and is the original of one of them, he knows how they think.
Yoglabs Xephos has no remorse for the wrongs he's doing, because he believes that he knows best. Israphel has that same ego, even slightly more adapted, because he's managing to corrupt people into his way of thinking. Which Xephos did with the employees at Yoglabs.
Yoglabs Xephos and Israphel also seem to recruit the same sorts of people. Yoglabs employees; Dr. Srivaramen (a mad corrupt scientist with an obsession with mutation), Prof. Brightmeer (the disturbing facial reconstruction surgeon), Voskoboynikov (a drug scientist, who tests on people without them agreeing to do so), Professor Bixby (a man obessed with scientic artifacts and understanding them) Gosencrantz (chief of cloning), Rildenstern (co-chief of cloning science), Bort (mutant zombie), Sascha (mutant creeper), and Dr. Lalnable Hector (the cannibal known for his onslaught of testicicates). Tally them up to Israphel's recruits, Reverend John (corrupt religious man, who mutates Granny Bacon into a zombie), Templar Enoch (obsessed with scientific artifacts and understanding them), Skylord Vitali (the vampire who goes on a killing spree on Skyhold and eats all his friends and family), Jock Fireblast (a pirate obsessed with fire a chaos), King Finbar (an undead, dwarf king who converts dwarves to zombies), Kormag Darkforge (a corrupt dwarf, who assists Finbar), Creeper Boss (an undying creeper), Zombie Boss (an undying zombie), Evil Honeydews (corrupt clones of Honeydew) Grimjaw Slugface (an undead pirate with a need for power and greed for matrial possession).
And another point, a lot of the main yogscast members have an evil equivalent; Duncan and Lalnable Hector, Sips and Zips, Honeydew and Evil Honeydews, Kim and Specimen 5, Sjin and Strawfingers (because Sjin created Strawfingers), so then there's Xephos and Israphel. It would make sense to be a parallel.
Also, Israphel runs to hide in the sands... Ironically where the Yoglabs facility is buried. And also wear Israphel traps Professor Webley Grizwold in a cloning vat.
And finally, Israphel's skin being updated to be wearing the clothes of Yoglabs Xephos.
And that's about all the evidence I can think of, off the top of my head for today, of the reasons that Yoglabs Xephos and Israphel are the same person.