Di...did I really just see Touta do Dio's pose lol.
"It's creepy, but it does look like a vampire!"
So Touta is basically a cross between Negi's Magia Erebea and Asuna's Magic Cancel (though not necessarily inherited from those two).
That's what I understood out of the chapter. Though I'm secretly hoping it's inherited from those two. Regardless of the implied incest, I really liked Asuna and Negi. If it wasn't for her being his aunt it would have been the best pairing next to Negi/Eva.
Both Magics come from Negi. Negi gained ME from Eva Scroll and inherited Royal Magic of Mars from his mother Arika. Asuna Kagurazaka only used fraction of Royal Magic and most people called it Magic Cancel since it protected Asuna from harmful magic.
Neither Negi nor Asuna ever focused on learning how to use Royal Magic. They learned of its existence too late. Negi had Magia Erebea and Asuna Kagurazaka had Kanka.
After the events of Negima Negi could have done more reasearch on his mother's magic and maybe added some of it to his arsenal. It's not very likely since it would seem he lost to MotB in the end.
If Touta and his "sister" are really just clones then they might be an attempt at obtaining power that would finally destroy MotB or use it to control both worlds. They could also be MotB creation to finally gain an everlasting vessel.