I want to see Garling die, but I think it will happen a lot later, probably in the actual Final War.
Ju Peter will betray Imu at some point, too.
But, I believe V. Nusjuro will be the next to die, and do so when the World Government invades Wano for Pluton and to do a Human Hunt (mirroring the Kurozumi hunt). Imu stated that the Holy Land is lacking manpower:
I think Elbaph is only one of many ops the CDs/God's Knights are running, right now. I think Wano is also getting invaded, and is probably where the majority of their forces are going to end up, and this is a big reason the Holy Land is lacking power right now.
I view V. Nusjuro as a highly functioning, somewhat loyal Orochi: a man who betrayed Wano's people, for the sake of the future of the country, to keep Imu from destroying it. Why does Wano still exist today? Because V. Nusjuro is from there, and has a deal with Imu regarding the country.
Now that Imu has Uranus + Mother Flame, Imu will eventually try to straight up destroy Wano, before Pluton can be claimed.
Orochi was TRASH, but even he got pissed when Kaido said he was going to take over the Flower Capital. Orochi wanted to destroy every part of Wano that wouldn't suck up to him, but, even he sought to protect some part of the country; and was swiftly beheaded, before crawling back, to get beheaded again.
V. Nusjuro would be FINE slaughtering the entire Kozuki Clan, I'd imagine there's a shit ton of bad blood there over the Poneglyphs/the desire to open Wano up to the world and make it free. V. Nusjuro most likely views the Kozuki as optimistic, foolish, bumbling idiots (so, he's like most of the fanbase, LOL).
BUT, if Imu straight up tries to destroy the country? I think V. Nusjuro would rebel in that instance, and attack Uranus to protect Wano.
If V. Nusjuro DOES die, I hope Yamato gets his Shodai Kitetsu, it's a good size for her, it seems to be a Two-Handed blade, and is the "First Generation Ogre Piercer", a perfect sword for the Oni Princess. Also fitting as Yamato possesses ice powers like V. Nusjuro.
I think Shamrock will become a Gorosei after, mirroring Shanks as reaching the 2nd highest level in their profession (with the highest level in the WG being Imu, and the highest in the Pirate world being Pirate King).
V. Nusjuro will be our key to exploring Ancient Wano's history, and is a big reason we haven't gotten any Wano-based Void Century stuff.
I think V. Nusjuro is invading Wano right now, as Imu invades Elbaph, though.
Kuzan told the Marines/WG about Caribou telling Teach about Pluton/Poseidon, so now Imu/Gorosei are going to be forced to deal with Pluton's existence. If the Gorosei (especially V. Nusjuro, since he's from Ancient Wano), are aware that the borders going down will activate Pluton, it also explains why Imu has never attacked the country: if the borders go down during an attack, Pluton Awakens, and they DON'T want to deal with that Battleship, as we know from Water 7/Enies Lobby.
I want crazy old bald man to do some cool shit, man.