.... Ya'll keep annoying me by ignoring GK as Nyarla ima have to strong arm you into listening. Let's see, soul of the outer gods... position as Gatekeeper, compared to Warden, if you look it up, is the same job duty, even in the dictionary they are the same actually
Warden 12 A gatekeeper
Gatekeeper 2 guardian; monitor:
GK is obviously a previous version of the Odin/Merlin/Harry rotation right? Do we all agree on that much btw?
GK's appearance is actually a mantle from when he has human/mortal, It's the gooey center that let Uriel transubstantiate.
Some proof is in the scaring on his face, a wizard would have healed over the centuries until it was faint but Harry describes it as deep. But also why he's connected to time and knowing the future, He's on a similarly Outside time existence, in fact, quite literally parts of him are beyond time, the Old God's part. It's why he see's time differently and see's future events.... and why he stays out of it mostly except like Uriel or even Odin, to
enable a choice.
Back to the Soul of the Old Gods, he's known for having thousands of forms, that's why his mortal form is his usual Mantle when he makes an appearance, when reality is unbalanced he's the first thing to manifest that imbalance. He's their soul because like with the fae mantles his soul is attached to their spirit, he's the host. His timeline ended opposite Merlins, instead of creating a prison by sacrificing his soulfire into a construct(look at DR again... Death Blessing indeed) he contained them within himself.(a prison is made in each rendition of reality, slightly different, but similar. Hades, Hell, DR, Gatekeeper.....)The darkness within the Joy he also contains, just like DR, Controlling the Ugly with the Beauty. It's why he can't step on DR, he's not from here and DR remembers this.(there's a lot more to that but that's for believers anyway lol)
More stuff, someone go ahead and argue this one please, I'd love proving what I know on this one....
*OP, the 5 LC gods would easily align with the 5 main celestial Bodies in Greek astrology, the 5 epochs in Mesoamerican mythology, ect. So... mayhaps?