I would create a space beyond and make most fiction real excluding Omnipotents and observe my creations on a screen
and destroying any threat that gets too strong in my Omniverse.
And use the concept of death to allow living beings to die then allow their spirits to move on to the next realm.
I would use this to have the power of anime characters then i master with Ability Mastering and imprint them to my body Ability Imprinting So i would use powers like Supersaiyan Blue ,Star platinum Crazy diamond Echos the world sticky finger stand, Dark dark no mi,Maguagu no mi, Titan shifting, Rinnegan, Eternal Mangekou sharingan, Byakougan, One for all quirk, half cold half ice quirk, overhaul quirk, Alchemy from fullmetal This is Absolutely interesting in my opinion
Same ^^
I'm more of a Complete Arsenal man, myself.
I'll create my own verse with my own history and I'll erase my omniscience to see what happens inside the verse without spoiler. If I get sooooooooooo boried, maybe I just create the strongest villain and a hero (but the villain will have 700 years old and the hero just 2, I want that the hero live in a dictatorship), then I'll see or maybe help the hero (but without all my power, just basic abilities like fire manipulation and healing), and bruh, see what happen
In the current world I live in? Not much, probably just doing nothing, I would probably just sit and watch outside the universe and meditate on power and corruption, rather than actively changing the laws of the universe and causing unforeseen consequences that, although, can be undone, would make me feel like an asshole for doing in the first place. It would be like killing Paarthurnax in Skyrim except this time, every quest I have is killing Paarthurnax in Skyrim. Yes, a simple reload would fix it, but it sucks to even experience it to the point that by the time you're restoring it, you already realize you fucked up. Stopping evil, preventing suffering, all that, even though you may think that as a "heroic" action, but I am a firm believer of "actions that try to stop something bad on such a scale can cause a worse thing to happen." Even if you can improve lives and all of that with no backlash via bypassing logic, you would still restrict the free will of everything in the universe as soon as you use this power to make a single major change, and if you fix that, you would have changed how the universe works so much that it's no longer the universe that you used to know. With unrestricted power, comes infinite responsibility, or no responsibility. I'm going to go with the latter... by doing absolutely nothing at all, at least for our current universe.
Of course, that doesn't mean I would just do nothing everywhere. I would probably recreate multiple fictional realities that I know and love today, and have fun in them, since I don't have a sense of guilt attached to them and know that they are only my creations. So what if I accidentally knock down the equivalent of a LEGO tower or delete my first minecraft wor- (realization that I fucked up)
Oh well, I can always restore unwanted changes (only for me) this time, since I can do anything.