I will try to be as of now kind of semi legit
In terms of AP Demonbane looks like to be slighly above baseline (able to create and destroy universes with his clashes), Goku has a bit more of scaling with him > Jiren > Beerus > Kefla/Toppo/Vegeta Evo (roughly all in the same ballpark) > Aniraza > Casual Jiren > Infinite Zamasu (who was a literal living timeline). Which means Goku is abit above
With speed equalized, we have Goku who has reactionary dodge and Demonbane's bigger size, but given the opponents are either FTL (Demonbane) or MFTL+ (Goku) the size should be semi irrilevant (see: Giga Bowser, although admittedly there was not such size difference), but we know Goku has fought big opponents such as Ozaru and Aniraza
Which of course means it's time to use HAX.
On that point, we have no doubt, Demonbane edges out, but are these capabilities enough? Let's see
Teleportation - Goku has IT that is similar and is willing to spam. Demonbane seems to use Teleportation less IC
Energy binding - Not the first time DBZ characters face paralysis
Atlantis Strike - durability bypassing attack that warps space time. Could **** up Goku real good if he doesn't dodge
Big Sword - Not much
Illusion Creation - Good question if Goku can be messed up or not by that.I remember it was argued he should be able to instinctively know,but let's put a maybe
Big shield - Flanking attacks
Homing shot - I am just asking, can Itaqua target an opponent MUCH SMALLER than itself? I think ki blasts should destroy it
Shining Trapezohedron - If that hits Goku, that's automatic, but I am not sure how quickly Demonbane would pull it out
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We also have Demonbane Regenerationn, but it seems it will give no real advantage, the Black hole creation (irrilevant as Goku should be able to outrun them), not sure how much Casuality manipulation is used mid attack, and attack through space time (should be dodgeable)
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Overall Goku has superior stats, less willingness to use hax (I dont think he'd use a Mufaba or even the Paralysis on Demonbane) and MUI would drain him relatively fast, while Demonbane has more hax,but less capability of landing it due to all seeming to go hax. The shining trapezohedron should be able to seal Goku but that would put DB at a disadvantage as both would be running down on fumes.
Goku can potentially one shot it with a Kamehameha, so I give a vote to Goku, but barely, at 55/100, but Demonbane has a lot of chance to win (Also, having Goku with Demonbane as notable victories would be hilarious)
Of course, if it turns out Casuality Manipulation can be used in combat... yeah, I am giving it to Demonjane