So the first thing you may think after reading the title is why use swords if guns are safer and faster (for solo play). That's certainly true but how fun is gunning the Duke after your 100th FSC run? Same ol' thing, right? With swords, it takes much more concentration, better timing, and most important of all, it's more fun (in my opinion). Hopefully more people that have dedicated themselves to swords will start actually using swords more often on Vanaduke instead of switching to guns.
Gear:
Feel free to switch anything out if you're heating, but be careful switching out Vog as you'll be on fire a lot if things go wrong with Vana like constantly charging, misclicks, etc.
Set: Vog
Shield: Barbarous Thorn Shield
Swords: DA/5* Brandish, Dread Venom (MUST), FoV (For trojans, slag mobs, you know the drill), AP (Wheelers/Turret Room easier. Can switch out.)
Trinkets: Elite Slash Modules
My friends and I have done testing with how much DPS swords do to Vanaduke. BTB/FF does the most followed by a Dread Venom close behind. The reason to bring a Dread Venom for solo is because you can circle around Vana and attack while moving in sync with the fireballs. This is very hard to do with a BTB/FF. DVS also helps the mask phases go by much quicker.
Vials:
This is easy. 3 health Capsules, 3 Remedy Capsules, 3 Stun Vials, 3 Mecha-knight/Shock vials/Poison Vials. (Mecha-knights are more important so switch out shock/poison for them)
Mecha-knights are a huge help because if you have atleast two and place them carefully at the start, they'll branch off and attack the two slag spawns to the left and right of Vana. This will allow you to dance with Vana as much as you please. The knights should survive after the phase 3 slags spawn then die after.
Strategy:
Most damage to Vanaduke's body will be done with a Dread Venom Striker. This guide is mainly focused on speed. Feel free to kill zombies before killing Vanaduke if you so desire.
Phase 1:
If you have any mechaknights, use them now. Charge your FoV for a nuke right at the start. After I charge, I usually throw a stun vial in-between where the slags spawn to knock both of them back. This gives me a lot of time to dps because the slags on the other side will have to reach around Vana to get to me. If any slags get close, shield bump them. If a slag is breathing fire on you, do not try to block it. You'll just get swarmed faster. Run up, shield bump the slag, then continue DPSing.
Phase 2:
As soon as you stop damaging Vana, grab some water and hit the mask with it right as it comes out. Once the timer reaches 1, run to the NW (this is where the mask will wander so it's faster) water spawn and hit it again with that. It should be over after the second water throw.
Phase 3:
Hands down my favorite phase. At the start of this phase I get an FoV charge ready to knock out 2 slags right off the bat. One usually lives but finish him off after. Finish off the rest of the slags before doing anything else. This is where the fight starts getting a bit tricky. It takes practice. What I do is douse 1 ball, then spin around Vana in sync with the other balls so that they can't catch up. You'll really have to keep an eye out for shadow fire. If any shadow fire spawns next to Vana, back out right away and douse it. Douse another ball after and get back to DPSing. If Vana charges at any point, you'll have to lure him back to the middle (You can get REALLY unlucky with charges sometimes). Just remember, douse 1 ball, get rid of fire next to Vana, and stay away from walls.
Here is a video that shows Phase 1-start of Phase 5. This is what happens if you get unlucky with charges. The run was still successful, it just took longer due to bad luck.
http://www.youtube.com/watch?v=GAPcgLCDTMI
If Vana does nothing but charge you, just start putting out more fireballs and DPS him against the wall. Back out if a ball is coming up on you and dive back in when it passes. I didn't have my auto target set to a key at the time of this video. As others have already stated in the comments, make sure you use auto target with shift.
Phase 4:
Same as Phase 2.
Phase 5:
This is actually easier than Phase 3 if you think about it. Watch the video and see where I stand to spawn kill the first slag guard. Charge again and get the second one as it comes by. Douse one of the inner flames and ignore the outer flames. Be careful moving in to start spinning because those outer fire balls will sneak up on you if you get greedy. The rest is pretty much just spin2win.
Would ice vials or Glacious charge help setup for getting him in a loop?