question about the crime bureau

[Sol]

I got relations to 60 presently after joining them thrugh the intro quests, the quest feels a bit out of place because the leader wants me to destroy one of three sects and the two of them iv found have leaders at level 70 and im just around the mid twentys

so as far as i can tell the quest would reward the bureaus ultimate skill, what does the last quest from the leader at level 100 reward? aside from the purple sword and blade manuals is there anything else worth getting the bureau to max? because i heard that sect hopping was good but the bureau feels like a bit of a trap with the way their questline worked out giving me a lategame task in the middle relations.

[Glenn]

Level up by training at the dude at the back. 20 is way too low for anything.

The top ability for me is the immobilise skill. Only place in the whole game to get. Ideally max it to carry to the next game. Their ultimate skill is absolute horse crap. Their passive which gives 15% accuracy can be useful depending on your difficulty. At the end you can recruit the sect leader which can be useful in the mid game.
A hidden perk is that once you get to a high enough relationship with the sect, you can buy purple swords once a day from the vendor at the back. When you hop to langya these can be used to improve relationship with the sect leader easily.
And oh, if you like the lady you should marry her while you are in the sect. She cannot join you any more once you quit.
But yeah, I agree the bureau is the worst one of them all.