Kylo vs Darth Maul

Standard Fight

Both can use force and sabers.

Maul gets his dual saber.

Maul

Maul easy

Id solidly support Maul as well.

Maul wrecks him.

As impressive as Kylo's force powers are, we never see him use it against a full fledged Sith or Jedi, whereas Maul was able to take on two at the same time. So yeah, Maul.

Maul in sabers easily. Ren's displayed more interesting and useful force powers but as stated earlier, they weren't used against trained Jedi or Sith so they might be useless against Maul.

Going with Maul here. Hopefully Kylo Ren will get more impressive in later films