I look through a bunch of resources and this is what I found. I did not do any testing, I simply compiled information. Also we have a Discord where I will be posting guides on team compositions and weapons for Razor. Discord: https://discord.gg/6qGZNQkWBX
Set: Gladiator 4
Feather – Flat damage
Flower – Hp
Headgear – Crit rate or crit damage (whichever you need to maintain the 1:2 ratio)
Time – Attack %
Cup – Physical Damage Bonus %
For substats prioritize crit rate and crit damage. After that look for attack % or elemental mastery.
Why this works: This is the most balanced build that allows you to deal damage with both your normal attacks and your e. This also allows for a flexible team composition.
Why this is bad: Gladiator set can only be farmed from world bosses. 5 star artifacts from world bosses do not drop at 100% even AR 50.
Electro damage build
Set: Thundering Fury
Cup – Electro Damage Bonus %
Why this works: This focuses on elemental combinations with Razor, so you deal will more damage with his e. You should also run an anemo support with Viridescent set and another support with Noblesse Oblige. A pyro support for overloaded damage is also good. A combination of these sets would allow Razor’s e to deal a lot more damage.
Why this is bad: Deal a lot less damage with your normal attacks.
Pure physical damage
Note: This wasn’t from my research, there are no sources backing that this is a good idea.
Set: Gladiator 2 + Bloodstained Chivalry 2
Why this works: This focuses on Razor’s normal attacks and only his auto attacks. You should use Diona on your team and give her Retracing Bolide 4 since this will 40% bonus normal damage to Razor when he has the shield. You should also run 2 pyro characters since this will give you a 25% increased damage from elemental resonance.
Why this is bad: Deal very little damage with Razor’e. While this maximizes Razor’s damage, your overall team damage might go down since you aren’t using elemental reactions as much.