Well, I see your character's behaviours and powers, and I can say that, in the actual time that I'm posting this message, there are a few characters in my cast that can be challenging for him if they really want to, some even can defeat him.
Let's start with Feith and Agnou
They're both magic users and each one has his own personal advantages, Feith can copy the knowledge and experience from others while Agnou can enhance the damage from his spells, with the right mindset each one of them can easily defeat him.
Then, we have Noone
He copies the powers of anyone around him, so the fight would be toe on toe, but he still a kid, so his mindset may be a problem at this moment.
The worse that you can do is fight against Irokah
If he wants to win, better to ignore this kid, he may be inexperienced, but his powers are extremely dangerous, so better to avoid any fight with him, he can't hurt your character if your character doesn't do anything against him, but if he hurts him, well, it may be the end of the world, or even the universe.
Your character may be fast, but she can teleport, levitate and manipulate crystals as shield and weapons, a fight against her won't be easy at all.
And as a character who can be match and even overpower him, is Rohe
Her powers allow her to alter biological structures, so she can heal herself or alter your character in any way or form, she may crush him like paper, she can weak his bones, she can even confuse him manipulating his emotions, she can do anything and keeping distance is not an option because she can stretch herself to reach your character even by surprise, All of this and more, if she is in killing mode.
And as Bonus, a Bioversal, the Reather
These creatures are extremely dangerous for the 90% of living beings on the planet, they can survive almost any attack no matter how hard the impact is, they can turn themself in any element to counter the enemy's powers, they can become intangible, they can turn their tentacles in drills, they can shoot lasers, predict teleporters next locations and speedsters routes and even eat souls if they realize their enemy is very resistant, they act quickly, once they discover what enemy's powers are, the battle is decided.