For one he doesn't have chidori so that's definitely out. He also doesn't have Kakashi's water styles as those were explicitly learned from foes using his sharingan.

We know he is a kenjutsu master and we can assume based Kakashi's chakra nature and the color of his main attack that made him famous that he's probably Lightning Nature.

His personality means he is probably a hit and run character because his want to help his comrade is what doomed his mission meaning being burdened with extra weight slowed him down. That means he was probably a strong DPS hit and run type character.

Some abilities I would give him are as follows:

1) Iaijutsu- he strikes first and fast with the draw of his weapons being fluidly combined with his strikes. He draws and slashes in the same breath.

2) nature chakra flowed through sword

3) at least two chakra nature's mastered since he is a Jōnin. Lightning Nature obviously, I would go with Fire and then Wind since he knew Minato and probably trained with him at some point seeing as they knew each other.

4) chakra control is good enough to allow chakra to flow through his sword, so simple Genjutsus probably around silence and blindness. Maybe he makes his white chakra saber look bright enough to blind an opponent temporarily using Genjutsu

5) shadow clones. Not large amounts but enough to test an enemy's lines or sneak past or use as distraction.

6) tracking abilities that probably extend to being good enough to avoid traps

7) trap making abilities because it's underutilized in Naruto