Sorry guys my computer broke so I won't be posting that many chapters as i planned this summer break.
but for now I can clear up some things
"Although I felt like the Gear 5 thing didn't make any sense, I mean, yeah, he was hit by radiation, but should that really cause an awakening? I don't see anyone in the story who is capable of awakening Luffy's Gear 5 like Kaido."
In my opinion, it kinda makes sense, and here's why:
So, the first time Luffy was hit by radiation, it caused him to remember all of his adventures, which is why he told the bizarre stories to Kaseki, like him being on Zunesha and all these other things that, in the world of My Hero Academia, would be impossible.
The second time he got hit by radiation, it wasn't his brain remembering everything that happened, but his body did.
So basically, in that moment, he felt everything—the pain, the joy, the sadness—all rushing in at the same time, which caused his heart to stop.
Since his body remembered everything, his body also began to reproduce the DNA Kaseki originally replicated (Nika), and then he awakened Gear 5.
In my opinion, it makes sense, since I don't see any other character besides All For One being able to awaken Gear 5. Maybe All For One, but at the same time, Gear 4 Luffy could still potentially beat him.
So, I decided that Luffy will have this ability from the start since he already can defeat anyone from the start with Gear 4 alone.
See you hopefully soon