MoldyDwarf's 2.4 BV+CI+PF

Here's the gear I'm currently using for Shaper farming. If I stacked a bit more mana (1.6k now), I'll drop Kiara. I still use it because it helps with the rare short stun I take from huge hits, and it's a silver flask. In easier zones, I use a magic silver of adrenaline.

level 95 tree (current, using skyforth)
old level 94 tree (no skyforth)

• Question: What's the 2nd most important thing with this build?
• Answer: Having a high ES pool is the 2nd most important consideration. I put this question first since a lot of people might think it's actually the most important. If you can get 10k ES, you can tank almost any single hit in the game. Stuff you still can't tank: phoenix discharge with extra damage, uber double flameblast, and other highly telegraphed attacks. You can tank things like Shaper's slam. I haven't run many Palace maps, so I don't know how hard those hits are.
• Question: What's the most important thing with this build?
• Answer: This is a boss farming variant of BV, so the most important thing is sustaining 100% uptime on the Vessel of Vinktar flask, even on bosses with no adds.
• Question: What's the 3rd most important thing with this build?
• Answer: You want enough lightning damage to out-leech any sustained damage. BV fights in melee range, so you have to be able to overcome damage. This is 3rd most important because if you can't sustain Vinktar or you die to a oneshot, no amount of leech matters. To get good leech, you want to have a conversion vinktar and stack physical damage on BV. One other approach is to use Physical to Lightning: great for phys reflect maps but bad for true DPS since bosses usually have high res but low armour. Other things that can boost leech are Warlord's Mark (also gives endu charges) and Atziri's Promise. In some situations, it's useful to augment your leech with one or two of those options, especially in fights that require a lot of dodging.
• Question: Great, so how do I sustain my flasks?
• Answer: For mapping, just about any pathfinder BV build should be able to sustain flasks. Isolated bosses are where it gets hard. The best way to do all of these (assuming you don't have a legacy Vinktar):
  
  • Get Primal Spirit, Arcane Chemistry, and Druidic Rite on the tree. Most BV builds grab 1 or 2 of these, and that's why they can't sustain on bosses.
  • Use Master Alchemist instead of Veteran Bowyer and Master Herbalist. VB is good for clearspeed, but it doesn't help much for bosses (the 100% thing is only on kill). There are two reasons to ascend this way. One is the alchemist immunities give you a lot more flexibility with your blue flasks. The second is the minor "Flask Effect and Charges Gained" nodes. The "charges gained" stacks with Master Surgeon and makes a huge difference in sustaining flasks. MH and VB are better for clearspeed, MA is better for bosses.
  • Get a belt with "reduced flask charges used" and divine it to 20%. If you can also get "increased flask duration", that's great. 20% reduced charges is much more valuable than the 50% increased charges gained from The Magnate. This is because you're already stacking a lot of increases on the tree and they're additive. Reduced usage is multiplicative when it comes to sustaining.
  • Get high crit chance on your BV. If you have an infinite budget, then cap your crit. Otherwise, try to get 60% or more and use a diamond flask. 60% + diamond = 84% effective, and 75% + diamond = 93.75% effective crit chance. Crit chance is important because (a) it increases the number of Master Surgeon procs and (b) it increases your DPS so you get more leech.
  
  Another approach is to use the Overflowing Chalice flask, but that requires sacrificing a flask slot. I use Chalice on Uber Atziri because she runs around so much and switches phases so fast, it can be hard to hit her enough to sustain without it.
• Question: How do I get enough unreserved mana?
• Answer: I like to have enough unreserved mana for two casts. That's plenty to clear maps, and I avoid being unable to use shield charge, etc. This is plenty because I always have Vinktar up and the 20% mana leech makes it easy to always be at full mana. When my gear was worse, I also used Warlord's Mark (quite useful on no-regen maps). A helmet enchant with reduced reservation is useful, but not actually necessary.
• Question: Why don't you use Discipline?
• Answer: I have 10.2k ES without discipline, and that's enough to avoid oneshots. I'm better off with more damage to shorten fights. When my gear was worse, I used Discipline.
• Question: How do I get enough cast speed?
• Answer: If you can sustain 20 blades with Vaal Clarity (or with vinktar leech on bosses), you have enough cast speed. This is a tank build and you should be sitting and spinning on bosses. You should only need a few blades to oneshot most packs in maps.
• Question: BV is so slow and annoying to play, how do you stand using it for mapping?
• Answer: Don't try sustaining 20 blades when mapping. Hit a pack or two, shield charge, cast a blade, repeat. That's usually enough for white and often blue packs. You may have to alter the rhythm a bit depending on the map and your DPS.
• Question: What map mods can you do?
• Answer: Blood magic and no leech are the only two I cannot do at all. Physical reflect is annoying but doable if I'm careful and/or I swap in Physical to Lightning. Elemental reflect isn't a problem. No regen is a little annoying but manageable with flasks - it's helpful to either have Warlord's Mark or a Vaal Clarity for emergencies. Other than that, just super-bad combinations like ele weakness + aoe + crit + turbo + -max on phoenix and stuff like that.
• Question: What alternative flasks do you use?
• Answer: Depending on the situation, I use Atziri's Promise (dps and leech), a ruby flask (uber atziri), Overflowing Chalice (uber atziri), surgeon's silver of adrenaline (shaper if I feel like it), etc.

Earlier in the league, I farmed Uber Atziri until it became unprofitable. Here's how to do it with this build. Doing it deathless requires good skill and good gear. Always use Concentrated Effect for all bosses.

Vaal Duo

Use Concentrated Effect and try to kill both at the same time. The second one gets harder once the first dies. This is standard advice for this boss.

Trio

The trio fight requires some practice. Once you get good at it, it's easy, but it takes a while to learn the timing and exact distances you have to worry about.

When you first enter the boss room, you can safely walk along the right and top edges for about 2 tiles without triggering the bosses. Learn how far you can step with normal Atziri.

Phys Rain Boss

The physical rain boss is the most dangerous for our build so it's very important to kill her first. Rumi's makes her less dangerous for us than many other builds, but she's still nasty.

• Approach the trigger line by the door but don't cross it.
• Activate Tempest Shield. It will heal you when the adds are launching spikes at you + regenerate your flasks, as long as your flasks stay up.
• Using shift-click (to prevent you from walking across the line), place a decoy totem in the middle of the zone, but slightly to the right.
• If you have Vaal Clarity, trigger it.
• If you have Vaal Haste, trigger it. Note that unless you have about 150% mana regen on your gear, you're probably better off using Vaal Clarity for this fight than Vaal Haste.
• Cast as many stacks of Blade Vortex as you can.
• Activate all 5 flasks (Vinktar, Kiara, Taste of Hate, Diamond of Adrenaline, and Rmi's).
• Shield charge directly to the physical rain boss.
• Hug the boss whenever possible.
• Keep your flasks up.
• Keep your decoy totem up. It'll distract the other 2 bosses.
• Keep your flasks up.
• If all 3 bosses are on top of you, charge away, revive your decoy totem, then isolate the phys rain boss and resume. You'll get oneshot if you let all 3 swarm you and the dual striker gets enraged.
• Keep your flasks up.
• Kill the phys rain boss either right in the middle or off in a corner. Don't let her die by the entrance. If she dies there and you rip, you'll probably fail.

Dual Striker

When the dual striker is enraged, he does a massive amount of reflect damage as fire damage. With our flask setup, you will rip if you try to tank him when enraged.

• Avoid the physical degen pool from the phys rain boss.
• Use your decoy totem to control boss locations as needed.
• When the dual striker is enraged, use shield charge and decoy totem to avoid it.
• Keep your tempest shield up. The adds will constantly shoot you, proccing tempest shield, that will proc crits, and that will regenerate your flasks very fast.
• In an emergency, charge into the adds to quickly fill up flasks. If Rumi's is active, it's better to let them hit you most of the time, but if you lose Rumi, they'll kill you, so wipe them out. Even if they're in the degen pool, vinktar (or Warlord's if you need it) will keep you alive until they're dead.
• Try to kill the dual striker near the edge of the degen pool, away from the door.
• The most important thing to optimizing the trio fight is learning when to engage the dual striker and when to run. It takes practice.

Cycloner

As a CI character, the cycloner's chaos trail does no damage to us. As a Pathfinder with Master Surgeon, we're immune to bleed whenever our flasks are active. This means the cycloner is the easiest boss for us.

• Don't stand in the physical degen pools.
• Keep Tempest Shield up.
• Keep your flasks up (see the dual striker section for strategies).
• Decoy totem isn't actually needed for the final fight, but it can make it go faster. Place the decoy totem between the cycloner and a wall. When he cyclones he's rush into the wall, staying close to you, instead of running across the map.

Final

If needed, replace Kiara and your diamond flask with a ruby flask and Chalice. It's too easy to kill bosses fast so you don't recharge flasks enough without Chalice. There aren't a lot of small hits so you don't have to worry so much about stunlock without Kiara.

Learn what hits you can tank. If you have decent gear, you should be able to tank normal flameblasts and fire storm calls, but avoid lightning storm calls and the double flameblast.

Don't touch the mirror, but try to facetank as much else as possible. Facetanking = more flask recharges = easier survival.

Even with practice, I found the final fight the hardest.