I believe Elbaph is a two part arc, and that we'll head back to Wano for Pluton soon.
The interesting thing to me is this page/panel:
"Overstay" implies the danger is time based.
If this means that Time passes differently in Elbaph than it does in the outside world, that means that when we leave, Teach might have already taken over Wano (but doesn't know how to activate Pluton, yet).
IMO Shiki is Mosa, but I think he's more geared for Pluton/Act 4, because Shiki wanted an Ancient Weapon in Chapter 0 (why he wanted to recruit Roger; Kaido/Linlin parallel, two Yonkou and an Ancient Weapon). Shiki will be big in Elbaph, but not huge.
I think Zoro stills kills Kaido in Act 4.
Loki doesn't know that Kaido and Linlin lost, IMO: who gave him a WEJ newspaper? His human followers walking around in rotting animal carcasses to avoid getting eaten? No.
I think Loki wanted to ally with a Yonkou in the past, and that's why Shanks shut him down. Loki liked Lola, but, after Linlin lied, Loki (who IMO hates lying/disloyalty), wanted to ally with Kaido. I fully believe Loki is Kaido's brother, and that Loki came to realize this, and hated Harald over it, believing him to have given Kaido up willingly.
Linlin views Kaido as a brother...
Zoro still doesn't know he's a Shimotsuki; IMO, Zoro's parents went back to Wano, and died fighting Kaido, after they heard what happened.
Shimotsuki Kozaburo left Wano 55 years ago; Zoro was born 21 years ago, 1 year before Kaido fully took over Wano by killing Oden.
Zoro's father, Arashi, left Wano once he heard of Oden's death from remnants that fled Wano after Kaido took over.
Kaido killed Zoro's dad. Koshiro more or less knows this, but didn't want Zoro to rush to Wano to die, like he would have to get revenge.
Once Zoro realizes Kaido killed his dad and took over his country, and killed his relative, Ushimaru, he'll want blood.
Zoro killing Kaido, Linlin/Loki's brother figure, will cause them to unite
Loki + Big Mom will be big players in Elbaph Act 2 as villains
Shamrock is the big villain of Act 1, IMO; Garling might also show up, since we need to see his Youkai form after Imu gives him the EVIL POWERSSSSSSS
We also haven't see shit from Elbaph's Army; Linlin/Marines considered it to be the most powerful Army in the world.
Elbaph worships war/might: Elbaph's Army is in Heaven/Astral World.
From Arlong, to Enel, to Enies Lobby, to Wano, the bad guy is always in a palace at the top of the island they're conquering.
Elbaph's Army is the opposite of Saul/The Owl Library/Walrus School: they're battle crazed lunatics, who worship war above everything else, and miss the good ole days.
IMO, that's where Kidd and Shanks are; partying up in Heaven World, because Elbaph is indebted to Roger in some way and likes Shanks (might have to do with Rocks, since we know Rocks invaded the country, and nearly killed Loki, and Roger beat him). Since Shanks is Roger's kid, and Roger killed Rocks, the Elbaph Army loves Shanks.
The Elbaph elite hate Hajrudin because he doesn't have pure Elbaph blood, and his mother wasn't from Elbaph. IMO, if Luffy wasn't friends with Hajrudin, he would have been invited up to Heaven World.
The Elbaph Army is partying up there, celebrating Kidd/Law beating Linlin; I think Kidd hates Shamrock, not Shanks, so, Shanks/Kidd should have squashed their beef, and are drunk as fuck up there.
Elbaph's Army should be a big focus as enemies, as well.
Since Lighting/Fire are weaknesses, I believe we'll see Akainu here, at some point, and Enel. Aramaki just makes sense, too, with the Giant Tree Yggdrasil being such a key feature to the island.
So:
Elbaph Act 1 Enemies =
-Shamrock
-Garling
-God's Knights
-Shiki (and Enel if he's working with Shiki, which I think he is)
Elbaph Act 2 Enemies (Post Pluton) =
-Shiki + Enel
-Akainu + Aramaki
-Linlin + Loki
-Elbaph Army
Something in me screams Enel is showing up soon. Hope I'm right. I think Akainu is going to defect after Wano Act 4, and Aramaki will go with him. Possible the WG takes over the Marines directly if they keep fucking up like they did at Egghead.