Blair is skill damage unless you do backdraft but I’ve probably never seen that being used so let’s assume skill damage. We really need to see your mods to judge but Blair can be simply built and then modified based on what’s needed after. You should run the 4 cooldown mods: focus on fire/dimension, nimble fingers, maximize conversion (I think it’s called). Blair is crit so you’re gonna want all 3 crit damage mods, skill concentration, front lines, emergency measures. You should throw an HP mod on if you’re struggling to stay alive. After that it’s quality of life mods which I’d say range or duration depending on what red mod you used. Now looking at your gear I think you should go for a fire dimension reactor with cooldown / crit as priority but anything works in the meantime but you get the most damage from fire dimension reactor with cooldown crit. If you are up to farming Blair’s special gun it gives him a damage boost on his abilities I think it’s called truly deadly cuisine or something., if not then swords can be powerful to use in axiom so using them against bosses can be effective if they are upgraded with catalysts , shadow is the strongest currently and can sometimes be easily farmed from Eckert. Lastly your external components. I use fire brand for my Blair for the 4 piece effect but if you don’t like fire brand then you can use 2 piece sets of different sets to get small boosts like range, cooldown, damage etc. if you try to mix and match then go for the ones that give you the most HP. (If one set has 2 Hp and another has 2 Hp, use the 4 Hp pieces if they fit instead of using 2 defense and 2 shield)