Hello! Looking for novels with MCs that are the definition of "too strong." To give a reference, I really enjoyed books by Vihyungrang (Power Overwhelming, Song of the Void, Lament of the Fallen).

I've also enjoyed novels like Forgotten Conqueror, Speedrunning the Multiverse, Primal Hunter, Arcane Emperor, The Path of Ascension, and just about every novel under the "Strong Lead" tag.

I don't really care if the MC starts off already OP or gradually becomes OP, but I'd prefer them to have some sort of inherent advantage (reincarnation, affinity, system).

If you haven't already figured it out, I admit I might be looking for Gary/Mary Sues that can grant me wish fulfillment.

It'd be a bonus of the novel was heavily progressed so that I could really get invested into the world/characters. 

I don't mind books on KU or other websites either.

Novels: Chrysalis & Everbody Loves Large Chests 

The characters in both novels grow to be pretty OP, in my opinion.

Isn't that just about every novel on RR?  Heck, go to novel updates, set the filter how you like with an emphasis on shounen.  Then just go to town with the list of hundreds of OP MC fics.  You can probably search for the keyword "cheat" since all those fictions love to tell you about how the protagonist didn't earn their power, but instead randomly got them through cheating.  

Heck, RR search for the keyword "cheat" and you'll probably have thousands of fics to choose from.  

Webnovel would also be a good place to look.  All the OP MC stories post there as if by divine mandate flooding the site with them.  You can't click on a fiction that doesn't have an OP MC in it.  

Here's a couple IMO.
Unbound
Savage Divinity
Law of Averages
Metaworld Chronicles
Magic-Smithing
Dao of Magic
Defiance of the Fall

https://www.reddit.com/r/litrpg/comments/w1vj9x/litrpgmagic_with_overpowered_mc_recommendations/ Hope my list helps

Basically every story by Andur, start with Transcendence?. 

Try The Mook Maker.
https://www.royalroad.com/fiction/54442/the-mook-maker
It just started hence it is relatively short, only 13 chapters in.
The protagonist is certainly overpowered with his passive summoning power that gives him a horde of furry minions

I mean does a god fit that because a book called world keeper is good and it’s also a massive ongoing book

I'd like to throw my story into the mix for what may qualify as an OP or become OP over time main character. 

MC can die and resurrect. Has a unique class that gives extra loot rewards from randomly generated quests. Can upgrade feats and spells using a currency gained through leveling. Doesn't get hungry or even have to go to the bathroom! (How OP is that?!) Saying anything more would spoil some goodies