Neutral Lon'qu - worth 5*

You want +spd/-res if possible (my best is +spd/-def atm) and you want to run the L&D, Moonbow, Desperation build with Slaying Edge+.

His speed without buffs or seals hit 47 in this form, will double almost everything without fail ever, and will trigger Moonbow every single engagement.

The only character that competes with this same build is Athena who trades out 1 spd less, for 2 atk more. However she will usually be left with her Wo Dao+ anyways.

Lon'Qu in this case is guaranteed to never get doubled naturally by his speed and with his HP and defenses it would still take 62 physical and 59 magical damage on red/colorless to 1 shot him which is damned impressive for a mega speed L&D user.

Seems like a waste of resources on a subpar unit but if you like him for personal reasons and want to build him up, go for it.

With 17 def/res after L&D and no movement buff as a flier/horse, it will be difficult to keep him alive after engaging.

Swordbreaker is also very common and ranged units shouldn't have difficulty avoiding/taking you out, especially if they have a dancer on their team.

Also 47 speed seems like overkill with a +spd IV, would rather roll with a +atk IV and sit at 44 spd.

Neutral is fine, but he does want +Atk or +Spd really badly. With Slaying Edge+ he still hits 43/44 which is still good, especially with the added Moonbow Damage. But yeah, not having an IV is a fairly big bane.

Given his 3 star rarity, I'd wait for one with good IVs. Even though I know you like him, I don't think think it's worth the investment unless you've got one with good IVs.

Hope this helps, sorry I can't be more encouraging.