So... uu is going to be born today? Hmm...
Hmmmmmmmmmmm
Ok, this idea is pretty stupid but...
What if uu is... Cal. The alive one. But not yet. He's a split personality of UU as we have all theorized, and his plan is to transfer his soul to Cal, thus being "born" today. That's why he needs Dirk to toast his own Cal, because uu needs to make sure that he possesses the true "Juju" whatever that implies.
I mean think about it. The Jigsaw schtick. The Calmasis symbolism. His obsession with Cal. His murderous behaviour. It could work.