The elemental abilities on his page seem very limited.
Ranged Electro attacks like
Lightning Shuriken and
Bellowing Thunder are easily avoidable as Nyan would easily slip by them as he was able to
do the same to Drive Knight's repeated missile fire.
Geo attacks like
Starfell Sword, which is just him slamming a boulder from the sky wouldn't do anything but serve as a blindspot for traveler, as Nyan has shown
the ability to slip into boulders and rocks. If Traveler uses this move, Nyan would slip inside of it and the
surprise traveller by jumping out and slashing him in the chest. The shockwave from
Wake of Earth gets countered by the superior AP of
Nyan's Feline Retribution ranged slashes (which he can spam).
Anemo's air-based attacks would be useless here as well.
Gust Surge is just a
much smaller and weaker version of an attack that Nyan easily survived via slipping through the cracks.
What is Traveler's response to Nyan's Feline Retribution attack, which is a speed amp allowing him to
greatly outspeed Drive Knight who in a slower form could
consistently tag him.
The location via SBA is at Central Park, meaning all the buildings around them would allow Nyan to us them as places to hide inside and use his speed to spam Feline Retribution from any angle.
Nyan can also dura-neg Traveler by
entering inside his ears or mouth in order to cut him from the inside out.