His showings aren't the most consistent thing on the planet, to say the least.
His best feat is contending with Elbaba and the Wolf. He could physically hurt/push back the Wolf and fend off the BH's Transcendent Skill with an Orb technique, pushing both the pet and him back. The same Wolf was able to battle Cha and withstand his moves without much trouble (and those are attacks that one-shot Division Commander Tier High Rankers who in turn are much stronger than Assistant Division Commander Tier High Rankers)
His worst feat by far is "struggling" with Ren, just a strong Ranker who should be leagues upon leagues below Elbaba. You can chalk it up to him messing around to test Leviathan's powers (and this is probably it), but he also wanted to finish the fight quickly and was unable to do it as fast as he had hoped.
Another feat is him wiping a bunch of Kirin's elite troops in one Orb move. Each one of them was stated to be more powerful than a Ranker (making them Advanced Ranker level at least). Dowon was impressed by his power, and he also assisted her in dealing with the troops more comfortably, receiving a comparable portrayal to her. This one probably goes more in line with the first feat of battling Elbaba.
Overall, I think he should be close to the low-tier BHs. Far stronger than Division Commanders. So, not low even for High Ranker standards.
