Hamon doesn't basically come out of nowhere like Haki did considering it's deeply tied to the lore of the Stone Mask and the Pillar Men and Vampires...
Hell Nen came out of nowhere too when you consider how lackluster Hisoka and Illumi's feats were in the Hunter Exams, not to mention this whole...
1999 Yorkshin arc > 2011 Chimera Ant arc > Alabasta > Eines Lobby > original universe JoJo
But Hunter has low points like the childish beginning in the Hunter Exams/Zoldyck Mansion, Greed Island and everything from Election and onwards, far lower than any of JoJo's lows. OP's low points have...
Gero's spy robots should've still heard that Galu was training in the heavenly realm prior to the 23rd, and you need enough food for a year or two to be prepared when you enter. During Black's rampage people were all so short on rations that even Mai and Trunks were eating dog food lol.
The...
Why would they not? It's right above where Goku fought Tao and straight where he went after defeating Daimao. Gero's data should cover it. Future Trunks never tries yo use the RoSaT in the future world either, indicating it wasn't an option.
Baba escaped Boo's rampage which killed literally everyone else except Goku and Satan, which makes it hard to believe she wouldn't have done the same here.
The cyborgs probably blew up the Kami place. Goku not coming back for a day is a real head-scratcher, but then again so is Gohan not coming back even though he'd have been training in the afterlife.
Goten would win simply due to being able to fly, plus he has experience tagging someone stronger than him (Gohan) while Goku's never sparred with anyone stronger since Grandpa Gohan died.
The rights to the franchise belong to Oda's studio first and foremost. Similarly, Youn In-Wan and Yang Gyeong-Il were the copyrights holders of Shin Angyo Onshi (known as Blade of the Phantom Master when its movie was dubbed in the West). Shueisha and Toei Animation merely own the rights to...