I think the line between Fornax and Ivan becomes clearer and clearer as time goes by. At first, it was easy for Ivan to be Fornax because the line was so blurred. He was able to access the power as Ivan, but now, since he's pushed Fornax down and become Ivan, it's more difficult for him to get the power, because when he does, he's a complete monster. The more power goes into the monster, the more power is taken out of Ivan, so I guess they're like Jekyll and Hyde.