VISUALS
I like the helmet cover, it’s a nice touch I don’t remember seeing it in any other game.
His vibrant colors are cool as well because it’s easier to identify him on the battlefield.
The shield pattern on his outfit fits well and his overall look is excellent.
The only downside is his weapons lack shimmering effect as it was discussed here. New GK weapons' metal looks... off?
And the blade of the longsword is really too thick. The new anim which shows the sword by pressing the appropriate button is cool (I don’t remember the vanilla button). Those who didn’t notice it, we can rotate the weapon by moving the mouse.
WEAPONS
The longsword is a great addition, finally we have a working 2h sword what other Kruber classes can use, too. Its movesets are great, I enjoy using it, especially the heavy attacks of course. I prefer using it even when I have a fully charged ult and could use it instead.
I think all of its anims should be quicker by 5-10% to make more difference compared to the other 2h swords. Maybe with higher speed it could be used more often on GN instead of the exec sword.
And it’s quite bizarre this and the greatsword has the same reach.
Bretonian sword and shield is less convincing. His flame defense ability encourages using a shield but the bretonian shield feels clunky and its light moves are not good enough to use it against a horde. Especially the second attack makes it painful because it’s almost a vertical slash, undesired against a horde. The heavy attack and the attack chain is very good but it’s not needed at all because we use his main weapon for attacking armored targets.
The imperial shield light moves are way better and good against hordes so I use it rather than the bretonian one. The imperial sword and shield is the only real option if I want to keep a shield and use his 2 weapon options like in case of slayers: one against light the other against heavy opponents.
GAMEPLAY
At first the huge power bonuses seemed OP but not that much in the practice. Quests are quite useful. I think when we lose the books the appropriate bonuses should be deactivated and the quest should be active again.
The 10th level talent row is surprizingly versatile with real choices, very well made.
His ult is great and the options in the 30th lvl talent row are meaningful.
There are still things which should be balanced, like the stoicism which can be easily interrupted to be useful.
Knights in real history used pollaxes on foot which are very similar to halberds so GN should be able to use it. https://en.wikipedia.org/wiki/Pollaxe
Check the picture search mode in google for pollaxe for different… illusions. 
OVERALL
The class is definitely useful and feels different. It’s a good addition to the game.