"(this is honestly more of a test to see how two people who make their own versions of battle interact)"
The normal way I imagine it is that you have a weird paradoxical battlefield where both of their battle ideas interact, that's at least what I imagine for Sans vs. The Judge since OFF's turn based combat field is canonical.
In terms of this matchup... I don't really know if the Rubber Band would count as having a sufficient SOUL (which makes me still question of Flowey did their fights), but regardless assuming Rubber Band has a standard soul it would likely not need to dodge Mettaton's attacks as it can influence the ring system to force Mettaton to follow the system to attack it.
In this case I think Mettaton has a harder time and state doesn't have crazy durability so I'm giving it to Rubber Band.
Posted by GiverOfThePeaceBureaucrat on 26 July 2026 at 17:53.
I assumed he would work given I didn't see on his profile Soullessness or anything to imply he didn't have an essence, atleast according to the profile.
Other than that, Mettaton himself probably loses but I don't think it's an outright stomp. as when mettaton does get to attack...I don't think his attacks will care about the direct attack immunity giving it's hitting his....uhh...core of his being.