Sub stats: Colossus&ATK&Critical Mutiplier&Weak Point/Electric
This is a guide for gley-use executor and especially for gluttony. If u want to use gley execute more bosses, which in fact I don't recommend, probably u need to have more different pols, cause u will need different kinds of element.
I will give a detailed guide in gley's build later and show u how to fight gluttony. So in this guide we can talk a little more about executor gley's other usages. Like other colossus? I don't recommend walkers, their weak points are too high too hit for a shotgun. As for other human form colossus, if it has the same map as the gluttony, like Excutioner and Devourer, u can hook the pillars and shoot shoulder armor on them, or if it hasn't, just try to shoot their knees.
Bosses in infiltration and invasion? Really not recommended. These bosses are much smaller so it's nearly impossible to maintain weak point shot, u will lose many rounds and lose its passive. So better not using weak point mods now but u can see there's not much mods to put on. And u need to get even closer to bosses and that may be a life threat, these bosses will cast knock back abilities if u came too close, besides some of them have devastating damage and it could be more lethal in close combat. Perhaps u can try use gley and executor for truth legion, act as an electric specialist.
If that's what u want to do, then switch those weak point mods and put on dual electric mods, enhance and priority one, and switch real-life fighter to electric conductor. Still u may find u have one slot remains, and there's few choices u can make. Perhaps a recoil or accuracy mod? Plus some crit mutiplier too.
I think these shall be enough. Acutally I use gley&executor only for gluttony and sometimes devourer now for some fun(lol).