This is how you Lon'Qu

Regarding Lon'qu's refine, most people have been disappointed. I do agree that it may not be very original, but there is something very fun to do with him. And I believe, with his new refine, NO OTHER HERO does it better.

This build is based off of an old Ogma build of mine.

Lon'qu +Atk-Res
Solitary Blade (LnD refine)
Reciprocal Aid
Reprisal
Fury/Death Blow 4
Wrath
Defense Smoke
Brazen Atk/Res

Basically, you engage, take a hit, double, activate Reprisal and kill something. You take a huge chunk of damage on the return hit thanks to his paperthin defenses (this is actually a blessing here, wait for it). You usually won't die (+10 Lon'qu with Fury and LnD refine has a bulk of 78 physical and 75 magical with a res bane), and Fury will help lowering your HP further.

Now, you are (hopefully) sitting at or close to 1 HP. How is this build any good, you wonder? Well, because two crucial skills have now been activated. First off, Wrath will lower your Reprisal to 0 cooldown (thanks to already getting -1 from Solitary Blade). This means that every turn you will be firing off 25 damage specials (when you are at 2 or less HP), without the need of lowering your special cooldown through combat. As an added benefit, new skills that lower your special cooldown counter during combat have no effect on this - your special counter will always be at 0 once you've reached the 75% threshold.

The second skill that activated is the new Brazen Atk/Res, increasing your attack by another 7 to a whopping 67 (again, assuming +10 and +attack Lon'qu). This is unbuffed! It already allows him to basically oneshot an incredible amount of units. You should really insert this build into any duel simulator you can find to see for yourself how bonkers this gets. Def Smoke is just the icing on the cake.

This build has two obvious drawbacks. Being at 1 HP with mediocre defenses means you die to a fart. So oneshotting is all you will be doing, but you will excel at it. However, getting repo'd out of the way is a nessecity afterwards.
Also, Vantage. Good thing about Vantage is that you don't see it that often in high arena.
However, it is way easier to set it up with Lon'qu then it used to be with Ogma. Lon'qu has a much easier time lowering his HP thanks to his low defenses, and his speed reaches 51 unbuffed, all but ensuring a double on the first engagement. With his LnD refine and prf weapon, he also gains a slight advantage in attack stat over Ogma (36 over 35 base).

Anyways, I am very satisfied with the refinement for Lon'qu. Have fun!