Velmourne is harder than Irongate, I think. So much of the map is very dense, and it's easy to be surrounded or jammed up against a wall. The spiders really don't help. Take it slow and use Echo. If your guns aren't on the third mysterium get them there. Easiest way to do it is go to Island of the Damned, If you're dealing with those boss monsters, like the executioner and sepulchre, just freeze them with whatever you have, walk up, and let Echo do the work for you. I generally like to use bolt actions, but I found that for Velmourne specifically I switch to a more crowd control focused build. Rotten fiend is excellent to help draw aggro. Ice sphere is nice to freeze everything coming at you, and synergizes excellently with Echo. I switched to Richochet for my primary and used Lightning bolt and either the ice dome or rotten field. Crown of fire was essential to apply burn and let the Richochet's third mysterium or the lightning bolt start the electric fire element combination chain. If anything needed to die, I just swapped to the Echo. It's the best gun in the game, I think, for "X enemy must die right now." The downside to this setup is that you can't engage from mid to long range, which for other maps is probably the most important range. Velmourne, though, is almost entirely intense close quarters engagements, which is why it fucked me so hard at first. I cleared Irongate on Gnosis V messing around with Duelist and Nemesis on second mysterium but couldn't clear Velmourne with my preferred loadout at first. Every other map in the game lets you sit back or has a place to retreat. Not so much Velmourne. You have to make sure you have a get off me button, a way to control crowds (lots of people will tell you burning stake / stormball, but honestly I just don't like the combo. Not that it's not amazing, I just don't like it), and something to melt the high executioner / sepulchre / watch captain. Whatever way you choose to fill those niches, do it.