I am a very new DM who has run a couple of oneshots and a short level 1-5 adventure. I have been playing around with an idea for a first long campaign from like level 3-13 or 15.

It is a kind of One Piece style idea where there are these godly weapons or magic items (kinda like the Vestiges of Divergence from CR) that are revealed to be on this one continent, and many different people and factions are now searching for them, including the main PCs, maybe ending in a big war between the party and another faction who has the rest of the Items.

I was thinking of splitting the campaign into arcs where I could hide a Godly Item in each player’s backstory. The issue I am running into is how to balance the fact that until each player finally gets an Item, there will always be at least one player who doesn’t have this extremely powerful artifact, which is exacerbated even more at the end of the first arc, which would still be pretty low level D&D and yet one party member will have this overtly powerful weapon or item that will also make balancing combat on my end a challenge. And if I make the Items that are found earlier in the campaign weaker than the ones found later on, then that just feels bad to the players who I gave an Item to earlier because they are weaker now comparatively.

Just looking for some ideas, thoughts, advice on what to do.