I would say [Whichever Namekian that holds the title of Earth's Guardian has their potential maxed for so long as they hold the title.] Or [the way to link the earth's dragonballs without the need for a namekian as the guardian.]

the normal dragon ball's abilities and would probalby need the super dragon balls

Unless you have a plan to make this type of immortality required for plot purposes I do not see the point. For example you could get stronger wishes through using a wish to make the new guardian of earth's potential unlocked or making a wish directly to increase the strength of Earth's Guardian thus the amount or quality of wishes that can be made from dragon ball's linked to earth's guardian. If you want to give him op stuff have him wish for a biological version of the andriod's ki generators and/or a healing factor similar to perfect cell's or Wolverine's. Wishing for this near all encompassing immortality sounds out of reach without the super dragon balls.

While returning Gohan's arm doesn't bother me since he could have Bulma make him a mechanical arm similar to Full Metal Alchemist. The scars and what not is cosmetic. The tail if you do should bring some sort of difficulty with his transformations or anger control. As for immortality, that depends on the type. Ageless immortality is inconsequential depending on how long you plan to make the story. Regenerative Immortality like Deadpool would make him impossibly strong quite quickly due to zenkai boost. Immortality through Reincarnation would be interesting if it goes through different Dragon Ball timelines or into other worlds of fiction. I wouldn't find it interesting if you give him a Deathless immortality where if his body ceases to live his consciousness continues due to it making it less about being Gohan and more about a SI or OC who was temporarily Gohan.

How long is the childhood arc going to last?

I noticed this in last chapter too but shouldnt this be Hiyori not Hiyashi?

Ive commented on the paragraph where I noticed you needed to revise through the last 3 chapters. One added note is that a few times I had to reread a section because you transfer from a character's point of view to the narrators which is a bit jarring for a reader. Interesting story but due to DxD being the main title, it comes off as slowly paced. I am sure it will pick up but may add a warning for a slow start in your synopsis.

The hes and his' are in reference to her in this sentence for the most part and thus should be shes and hers

again not translated.

this is not translated.

Never heard of winhof. what is it?

Gabriel's personality is not really developed enough in my opinion to meet Sheldon as it stands. I feel like his personality would be heavily influenced by Sheldon making the story less about Gabriel. If Gabriel has a more developed personality that we as readers do not see, I would suggest finding a way to portray it before having Gabriel interact with any strong personalities.

Great Story thus far. A little too quick in pacing in my opinion due to the 5 year time skip where nothing to the reader's knowledge occurred that was worth while. I would probably recommend when you do the rewrite like you said that you don't just completely skip that time and maybe add a bit of his efforts during this time. Maybe he does a bit of classical theatre acting or a couple of gigs at bars. It just seems like 5 years is a bit excessive time skip in a world without supernatural ability or an ability to extend his life even if it is realistic.

This chapter is rife with awkwardly worded sentences for an English reader. It is readable but not how I would describe as enjoyable to read.

This is worded awkwardly in English. It still gets its point across but you wont find anyone speaking or describing a place like this. It could mostly solved by ending the sentence at the word education and adding the word locally before the word renowned.

Interesting start. You should look back over it though there are a lot of grammar issues for an English reader.

I see so its a wiki of what? I guess I will try to google it. When I googled SCP by itself it brought me to a bunch of random things that were unrelated to fiction. My first point still stands btw. IF you do not know what SCP is you are just thrown into the deep end. I kind of likened it in my mind to X-Files or a Law and Order set up, maybe even creepy pasta. Also there is no SCP tag so going in I simply thought it was a cross-over multiversal story. The only mention of SCP in your summary is at the end and only briefly. I found your story going to the Fanfiction then most recent and figured I would give it a try. I wasn't trying to complain either. I was simply giving criticism letting you know a flaw in your style. I agree with your point about you should be allowed to assume its a fanfic of this so you don't have to explain but you have a tag for FGO and FGO is in your title so I thought that, that was going to be the main world thus i assumed it was a fanfic of FGO not some SCP. I know what waifu catalog is as it is rather prevalent here on webnovel but before encountering it a few times I had no idea what it was outside of my assumption due to the words being pretty good descriptors.

Entering the story if you do not know SCP (like myself) you have no understanding what is going on. There is no real explanation of what is going on just horrific event after horrific event. No explanation of characters appearance outside of their fingernails. Knowing that SCP - and having no previous understanding or where to find the source - is the majority of this story as of current, I find the story lacking as a fanfiction. I know recently a new arc for FGO has begun but the question stands do i need to read the previous arc to read the new one? If not then why is it a continuation of the story? If yes then I would say it was executed poorly for anyone who doesn't have canon knowledge.

Had me reading it with intrigue till chapter 9 which is left field weird kinda like M.Night. Shamalan films. Hick ups in translation or the author doesnt know how language works. The story actually has a great pacing in my opinion. They rely on character design and world background of the original work until chapter 9. At the moment I am not sure this is transformitive enough to legally be called a fanfiction.

It's supposed to be Erised which is Desire backwards.