All important combo GCDs and oGCDs are on the face buttons for max mobility while weaving/doing positionals 

I tend to put AOEs on the D-pad since they aren’t as important but Viper actually has more AOE GCDs than most jobs, so Pit of Dread (aoe Twinblade starter) was able to get a spot on the R2 + Square since there was real estate. 

Hotbar 3 (L2>R2 and R2>L2) are mirrored so you can just mash the other trigger down after hitting a combo GCD and always have the same oGCDs (other jobs have enough space for this too, not just viper). 

Twinfang and Twinblood line up with the buttons that Hunter’s and Swiftskin’s coil are on which makes it easy to just press that button twice to start the oGCD combo chain. 

Role actions/sprint/LB are just where I usually put them, feel free to move those around. 

hampster2028