[ 3.2 ] Ice Crash Leech Slayer

The way Leech works is not very intuitive, so I felt like a description of the mechanics we are taking advantage of merited its own section. Our abuse of Leech heavily relies on the Slayer ascendancies Endless Hunger and Brutal Fervor, so I would not recommend taking Vaal Pact until you have them both (see the Passive Tree explanation below). Each hit with Leech gives an invisible Leech "stack". This stack has a heal rate property equal to 2% of the character's max life and a duration property based on the total amount that was leeched (total life leeched / rate of life gain = duration of leech stack). This means that a hit that deals more damage does not leech life faster, it only causes the stack created by it to last longer. Regardless of how many leech stacks you have, every character has a Max Leech Rate which is the leech rate that the total of all of their stacks leech rates cannot exceed. By default, the Max Leech Rate is 20% of Max Life. Then, finally, all leech stacks are lost when the character is at full life.

The typical way to use these mechanics is to just focus on DPS, and when the character gets hit and doesn't have full life, the leech stacks start building up. Most characters use this to supplement their other defenses, but a Slayer can take an entirely different approach. By allocating Brutal Fervor, the Slayer no longer loses their leech stacks at full life, and by allocating Endless Hunger, the Slayer can focus on damage per hit instead of dps, and then killing even just a few weak monsters can gain them leech stacks that can last for several minutes! It becomes trivially easy for a Slayer to keep themself at the maximum leech rate, and so this becomes a reliable primary defense, so a Slayer can focus their Passive Tree on having as much Max Life, Leech Rate, and Max Leech Rate as possible and essentially anything that can't kill them in 1 hit can't kill them at all.

Early Game:
https://poeplanner.com/AAwAAE0ADBQAACMFLQ48Few6UkCgR35eE2FSZU107XrvhNmE74Zgh2qK8JBsqSeplLkdvTa-p8qQ2sHpRu9O37_bT-DDJbwUcfjr6hj3MnzZAAAAAAA=
As you can see here, the first thing I like to do is essentially make straight for Resolute Technique early on. This build is not designed to have a lot of dexterity/accuracy, and with a slow-moving heavy-hitting attack like Ice Crash, it feels real bad to miss, plus we aren't really doing any crit anywhere, so there's no loss. As you can see, I also pick up Blood Magic* early on because it makes leveling way easier when you don't have to worry about the mana cost of things, and your life regen rate is going to be plenty to sustain your abilities.

*Why Blood Magic?


Preparing for 2nd Ascendancy:
https://poeplanner.com/AAwAAH0ADBQAADsFLQ48Few6UkCgR35eE2FSZU107XrvhNmE74Zgh2qK8JBsqSeplLkdvTa-p8qQ2sHpRu9O37_bT-DDJbwUcfjr6hj3MnzZdqzPfq2N2WGFUusJOQ4Jlpd55FFQR-8O2XyCB7yfGJEMcCefO7aFp4a0pTWygPVhAAAAAAA=
Until we get Brutal Fervor, we don't want to switch over to leech as our primary defense mechanism yet, so leading up to that we mostly just want to grab the efficient life notables off the path we have already made, plus a bit of 2-handed damage nodes to keep things moving along at a comfortable speed.

After Brutal Fervor:
https://poeplanner.com/AAwAALsADBQAAFoFLQ48Few6UkCgR35eE2FSZU107XrvhNmE74Zgh2qK8JBsqSeplLkdvTa-p8qQ2sHpRu9O37_bT-DDJbwUcfjr6hj3MnzZdqzPfq2N2WGFUusJOQ4Jlpd55FFQR-8O2XyCB7yfGJEhYHTxj2BvJ5pqI9NOKio4k6iKs1dUIVUs-4oiJyDcPQd1wKZyqcT2xq48LYPMtz7-Cti9rKpZ8xo4kFULYa9saPLwH6IAsoCGtIWnJ58AAAAAAA==
At this point we are ready to switch over to leech as our primary defense, so we grab Vaal Pact and a few other leech nodes (the "physical damage leeched as life" mods don't do anything for us, but they come attached to the increased max leech rate nodes, which are great for us). Then, we're ready to optimize our overkill damage, so we grab Executioner and Wrecking Ball. After that, things will start feeling real good, so we can take some levels to get some of our pathing to the other clusters we're going to want in-between the Marauder and Templar areas.

Late Game:
https://poeplanner.com/AAwAAPcADBQAAHgFLQd1CZYOPBQgFE0UcRXsGJEhVSFgJyAs-zGeNZI5DjpSOuE8LT38QKBGt0d-TeNQR14TXz9hUmVNbyd07XTxdqx673zZggeDX4PMhNmE74VShmCHaooiivCMz49gkGyXeZpqplepJ6mUrY23PrkdvJ-9Nr6nwKbGrsqQz37Tb9i92WHZfNrB3D3kUelG6hjrCe8O707yRfZI9zL46_xL_gr-jyPTTioqOCml37_bT-DDJbyTqIqzV1TE9nKprKpZ8xo4kFUnLwthr2xo8vAfogAEs8BmPAXvfPPdaGXyQQxwJ587toWnhrSlNbKA9WEAAAAAAA==
I usually like to pick up Kaom's Roots because of the excellent max life and immunity to slowing effects (freeze, chill, temporal chains, stun) but since they come with Unwavering Stance, I like to pick up Iron Reflexes (since I can't use that evasion anyways, it might as well be armor). Everything else on this tree is probably pretty self-explanatory. Since our hits are already insane, we go for life, and lots of it (plus a couple sockets for jewels).

Gearing this character is very easy and cheap. The only unique that is really necessary to get the damage conversion on Ice Crash up to 100% is Hrimsorrow gloves which are generally considered trash so you can get them cheap.
https://pathofexile.gamepedia.com/Hrimsorrow

You'll also want a 2-handed weapon with 6L and highest max hit damage you can find (not average damage, not dps, highest max damage. Works better with overkill from Endless Hunger). 2 handed weapons are very not meta right now, so you should be able to get a 6L for much cheaper than you'd think. When I looked, I got a very decent one for 10c and a great one for 20c. If it's still too early in the league and you can't afford this, you can get away with a 5L and then it's trivially cheap.

Another unique that you will probably very much want to grab is the Writhing Jar flask:
https://pathofexile.gamepedia.com/The_Writhing_Jar
This weird flask gives you an insignificant amount of life and mana when you use it, but more importantly it drops a couple weak worm monsters on the ground when you use it. I like to carry 2 and pop them both twice at the start of every new area, then smash all 8 worms at once to start the area off with a huge buffer of leech time.

For my boots, I prefer to use Kaom's Roots:
https://pathofexile.gamepedia.com/Kaom%27s_Roots
These boots have a huge flat life boost and make you immune to stun, chill, freeze, and temporal chains, all for the low low cost of sacrificing the ability to put gems in your boots and sacrificing the ability to evade attacks. The lack of sockets is meh, but to mitigate the inability to evade attacks, I like to grab Iron Reflexes from the skill tree (since my pathing brings me right past it anyways).

Essence Worm:
https://pathofexile.gamepedia.com/Essence_Worm
With Haste in the socket makes for a great quality of life boost in terms of using movement skills faster and helping offset the fact that Kaom's Roots have no added move speed. Since our tree focuses so much on raw damage, increased attack speed has amplified returns. Alternatively, you could put Hatred for another huge damage boost. Since we're putting this in Essense Worm, it doesn't hurt our life total.

Besides that, all the rest of the gear is just "get as much life as possible while keeping your resists capped". Nice thing is, since you're using a 6L 2-handed weapon, you don't have to stress about getting a bunch of sockets on your body armor.

Gem setup is not complicated. In my weapon (which is generally easy to get as 6L):

Ice Crash -- Concentrated Effect -- Elemental Damage With Attacks -- Elemental Focus > Melee Physical Damage > Ruthless

I put Ruthless in my setup for the same reason I suggest in the gear section to focus on finding a weapon with maximum hit damage, not just dps or average damage. This build really benefits from spike damage because of the Overkill factor of the Endless Hunger ascendancy, so that every third hit doing much more damage from Ruthless will give you a much longer-lasting leech stack.

Another gem setup I have that's pretty important to this build is:

Cast When Damage Taken (L1) -- Blood Rage (L7) -- Immortal Call (L3) -- Frost Bomb (L10)

Arakaali is one of the Major gods in the Pantheon, and after boosting it by capturing Arachnoxia in Toxic Sewer Map, it gains "50% increased Recovery of Life and Energy Shield if you've stopped taking Damage Over Time Recently". Life leech is considered a form of Life Recovery, so it is boosted by this ability. Putting Blood Rage and Immortal Call in the same link as Cast When Damage Taken can trigger this ability every time the CWDT triggers, as long as you make sure to put Blood Rage first, and then Immortal Call. This has the added benefit that you usually run around with a bunch of frenzy changes now. Frost bomb is added to the end to slap on some extra reduced cold resist on enemies periodically.

As far as movement skills, I am partial to

Leap Slam -- Faster Attacks -- Fortify

I mean, I suppose we don't really have much of a choice here given that we're going with a 2-handed weapon, but Leap Slam works fine. And if I end up getting this on a 5L chest, throwing Curse on Hit + Frostbite is real nice for some added damage.