Exactly what the title says: Show Off your builds, and Rate the builds of others.
I'll go first.
Arval: Arval's base kit, but with added C feud to give advantage against colorless units, with his usual C skill as a seal.
Joshua: Originally, I was just going to copy paste DC Code's Joshua build, but I made a couple changes. His refine gives a +4 to all stats, as does fury 4, during combat. Originally, I thought that bonus doubler makes the +8 into +16 to all stats across the board, but then I learned it only affects field buffs. Bulwark heals most of the Fury chip dmg, and menace, for a +12 to atk/def instead of only +6. (Technically a +18, due to the -6 atk/def bulwark inflicts)
Python: The bulky cav archer got even bulkier! Close reversal gives him +5 def during combat, A/D far trace enables canto, and inflicts -3 on atk and def, and menace bc menace is a nice tie in with the plegian bow+. Bracing stance also makes him a little more bulkier, and enemy phase proficient alongside close reversal.
Nino: This build is designed to stack tons of Spd onto Flying Nino. Stacking huge amounts of Spd is very important for her if she is carrying the Special Effect Refine for Giga Excalibur. Atk/Spd Push's self-inflicted damage makes it easier for her to fall into Desperation range and when she is there, she can easily take out lots of foes without taking a hit. If a flier ally is carrying flier buffs, it will improve her performance and also trigger the buffs on her weapon.
Yuri: Yuri's build idea is quick and simple: Kill with lethality as quick as possible. Special spiral, Time's pulse, and his PRF weapon decrease the cool down, Atk/Spd solo for buffs, and null follow up seal, cuz nfu is busted.
Yune (If all else fails): Yune is a last ditch effort, to let loose if I'm on a losing streak. Yes this build was taken from ZeShado. She's here mainly to complement Nino, due to also being a flying unit, so she gets the buffs. She screws other mages over with her refine and far trace, and by being close to Nino, she also gets unity boosts.