Why Dread Venom Striker???
Dread venom striker has normal damage with many hits, which means it has to get past A LOT of defense. For this reason, it has REALLY high attack power. These words are capitalized for a reason- its base damage is actually a bit higher than the brandishes, which is to say that as defense goes to zero, dread venom striker becomes the best sword to use for normal hits just about- since "weakness" is just lack of defense, this matters quite a bit- imagine a weapon that is super effective against everything. Yes, Iron Slug. But as a sword with a tiny range.
To get to this damage you need to boost yourself. Generally, this means bringing chaos/black kat and maskeraith with deadly cloak, as well as trying to find and pick up attack boosting orbs whenever possible. Having a friend with Drakon's boosting firestorm ability isn't a bad idea either.
Now, this damage isn't sustainable. Oh no. So here's our game plan-
1. Attack with other weapons, mostly bombs and guns.
2. Cloak after drop a bomb
3. Deadly shadow cloak + DVS an enemy to death
4. Rinse and repeat
Complimentary Weapons
A list of weapons that go well with DVS, from best to worst-
1. Dark Retribution (gets the full boost from mask's cloak)
2. Venom Veilor (makes DVS do a bit more)
3. Shivermist Buster/Voltaic Tempest (stops enemies, making cornering them automatic)
4. Blasters/Antiguas/Drivers/Mixmasters (ranged damage is safe damage)
5. Other damage bombs, including ash of agni
Gremlins
To begin, gremlins come in quite a few flavors which must be handled in quite a many ways. Generally speaking however, your team will handle the bulk of the gremlins before you have a chance! Your main task is to take out the gremlin menders while they do this, as they are the only real threat even close to being worthy of using dread venom striker on. Another noteworthy thing is that gremlins are weak to poison, which makes DVS outshine just about everything.
Menders: If you have venom veilor, ignore them and poison on. If not, dark retribution, cloak, bash to death. Dark rets takes care of the crowds a bit (with tons of excess damage from deadly cloak) while you sneak around to get into position. Failing that, just corner and kill. If its in the bubble you can even charge attack them, whatever works.
Thwackers: When the opportunity arises, dash or bash in, switch weapons, and attack. Most of the time however, you're going to be using an auxiliary weapon. Most of the time this is going to be dark retribution.
Demos: Attack head on! It's a bad idea to fight these but if you have to try to keep knocking them back so as to dodge the bombs they're dropping. Generally using other weapons is more effective.
Stalkers: Corner and bash, similar to menders.. but since they can go invisible, it's advisable to first drop a bomb, or tortoshield bash into them, or what have you so as to catch them by surprise. DVS is good against these, as it prevents them from hiding again and corners them easily.
Mortafires: Use a barrier to make them drop their shield, then use your dread venom striker to kill them. Alternatively, sneak up behind them with maskeraith's cloak, or just run around them frantically. There's no real way to fight these guys that isn't annoying and time consuming.
Oh yea, that flamethrower gremlin: These are like kittens just kill them EXTERMINATE EXTERMINATE.
Slimes
Slimes are vastly more simple. The general formula of dark retribution + dread venom striker applies very well and eats them alive. If you don't have dark retribution or deadly shadow cloak, it's possible to just corner them and bash away, shielding attacks occasionally. The other bombs mentioned above do a number as well, especially while your cloak regenerates if you do have that.
Giant lichens are a bit tricky, but are just like jelly cubes except bigger and scarier and random.
Bonjour
You forgot Electron vortex as the best tool for DVS, it compensates for DVS' tiny hitbox and lets you cut up crowds easily. Also, like you said, DVS has a lot of DPS potential, so I wouldn't recommend dealing with crowds through DR. EV let's you deal with crowds with the DVS itself, which allows you to focus your loadout purely on sword damage bonus. And that allows you to perhaps get a little more defense from your armor. I wouldn't recommend chaos gear at all though, it's wannabe black kat without the good stuff like MSI and max damage bonus, while it has all the bad stuff like shock and poison penalties.
I wouldn't use any of the mist bombs either because I find them slow, while DVS is all about moving fast. You get plenty of poison from your sword and your maskeraith anyway. One other sword I like using with DVS is Gran Faust, because it gives you that wide swing of big damage that you can easily combo into by swapping weapons. This covers pesky slime or gremlin thwacker hordes, both of which can be difficult to deal with if they corner you and your pet is on cooldown.
Thanks for reading