Dylan's AP is 1.9 kilotons, while Betty's AP is around 4.7 kilotons, scaled from Undyne, so Betty has an AP advantage. Their durability seem to be the same as their AP, so Betty also has a durability advantage. Speed is equalized, so I'll look at the hax to determine if Dylan is haxxed enough to defeat Betty.
Dylan can't really use his Power Mimicry, since that require Dylan to knock Betty out, which probably won't happen because the AP and durability difference. Dylan has a few ice attacks, and Betty isn't resistant to that, so flash freeze and freezing shard will work for a little bit (maybe 20 seconds in the desert). Dylan also have the thread attack, which can pin Betty to the ground for a few seconds.
Betty has a lot of soul/mind manipulation, but that won't work at all against Dylan since he's a robot. So Betty can't win using hax, and she can only win using pure AP.
I think Dylan would to use the clone button, which will create 7 clones like Ween. Then, one or two Dylans will use the freezing shard over and over again every 10 seconds, so that Betty can't attack. The other Dylans will blast Betty with the Dylan Buster at the same time, which because of the clones, will be enough to seriously damage Betty. The Dylans will repeat this until Betty gets killed. I do know that Betty have a healing factor, but the Dylan Busters combined will be around double Betty's durability. So Dylan will win this one, even if Betty has an AP and durability advantage.
