Voting either Medaka or inconclusive.
Goku has no reliable way of putting Medaka down for good. All Fiction erases her death, time, fatigue, and damage taken from Goku's supposed speedblitz. Medaka could potentially always come back while Goku has very high, but finite stamina.
I can definitely see UI running out eventually while Medaka keeps mastering his non-physical techniques with The End, such as Precog, IT, Goku's powerful ki-based attacks, in the meantime. Not sure how effective that would be since he blitzes her, but then again, Goku's stamina and UI do not last forever and Medaka just keeps coming back.
Otherwise, I'm not entirely certain if Medaka's hax can directly affect Goku. All Fiction could erase him altogether, Scar Dead could reopen his physical and mental wounds, Unknown Hero can affect his memories, and Book Maker could bring Goku down to her level should it bypass conventional durability, but it all depends if they can actually affect him in any way.
Medaka outlasts Goku. If any of her hax can affect him, then I think she eventually wins. If they don't, it's probably inconclusive. This is without taking The Hero into consideration even though OP said conditions are unrestricted (DBS has notorious instances of PIS involving Goku). Since it is 'win by death', I'd assume sealing is a no-go, though she probably can deal with that with All Fiction.
