A lot of the content of this post is going to be pulled directly from my thread over on the d2 subreddit on the same topic, but for visibility I wanted to post it here. JSP also has the advantage of allowing me to be more detailed in my analysis without auto-removing the posts.

With 2.4, lots of people are interested in trying out the new hydra for pvm purposes. There is speculation that Hydra may be a fantastic skill for doing boss runs (Meph, Andy, Diablo, Baal), but I haven't seen much in terms of concrete theorycrafting on the topic, so I did it! I don't want to bog this post down with math, but there will be some. This is mostly intended to provide information about hydra and its use cases against the 4 main farmable bosses in the game.

Out of the gate, one major advantage of hydra is the same advantage that meteor has- specifically that you can take Frozen orb and have access to a reliable second element to deal with fire immunes. To foreshadow, fire's biggest downfall is enemy resistances, so this is a big boon. But if meteor also has this advantage, should one just use meteor instead?

Ultimately that depends on what you want to do. If you plan on farming areas with fire skills (like the new Stony Tomb, which is a really great farming location BTW), then meteor will beat hydra. The fireball synergy that meteor provides simply can't be matched in terms of clearing speed. If you want to do boss runs, however, Hydra is the better choice.

First, a breakdown on how Hydra deals damage:

Hydra summons three heads that each independently shoot firebolts at targets. Hydra takes 1 second to "prime" before it begins shooting. After primed, each cast of hydra (three heads) will fire approximately 2.2 times per second due to AI attack delays. One can have 6 hydras up at one time. The listed tooltip on the skill represents the damage of each individual firebolt. So, to find the damage per second (dps) of hydra, one can take the average damage of the tooltip and multiply it by 13.2 (tooltip * 2.2 attacks per second * 6 hydras).

Hydra is affected by -enemy fire resist effects, including from gear, and from +fire skill damage including from gear.

**The Numbers**

A lvl 46 Hydra, fully synergized with max fire mastery, with no sources of -enemy res, using eschutas with +20% fire damage and no other sources of fire damage modifiers on gear, does 74k DPS. This is assuming 6 Hydras are up at the same time.

Adding fireball spam at the 105 fcr breakpoint (3 fireballs per second) brings that dps up to 114K DPS. Using 2 fire facets in gear brings this damage up to 125k DPS

63k max damage lightning at the 11 frame breakpoint does 71.5k dps on average

Blizzard, assuming 2 are stacked on a meph sized target and hitting it once per second each, with ice blast spam at the same 3/second rate, does 50k dps against an enemy with 0 resists (I know, don't worry I am going to address it) (testing done with death fathom and nightwing with cold facets in each)

What this shows is that against a single target at equal resistance levels, Hydra out damages every other common sorc option (it also outdamages meteor + fireball spam, but I didnt list it here).

The problem with hydra, obviously, is that enemy resistances cripple it. But with the above numbers we can create ratios to determine at what level of resistance hydra pulls ahead of the other options for boss runs.

Blizzard is basically always damaging a target with -100 resist, so its real dps is 100k. So if an enemy's fire res is at 10% (with no fire facets), Hydra pulls ahead at 102k dps. If you are using the 2 fire facets (+10% fire damage), enemy fir res needs to be driven down to 20% for hydra to match Blizzard's output at 100k. Any enemy fire res below 20% means hydra pulls ahead of blizzard. If you do not have death fathom and nightwing, obviously Hydra starts winning at higher resistance levels. With no Death Fathom / Nightwing (Hoto and Shako used instead, with a cold facet in the shako), hydra/fireball deals the same damage as blizzard/ice blast at 40% enemy fire res without faces, and 44% with fire facets.

For Lightning to match the damage of hydra/Fireball (63k lightning at 11 frame breakpoint), an enemy must be at -60% light res with no fire facets, and -75% light res if fire facets are used (assuming 0 fire res).

**Real examples**

Against Andariel, Hydra is always the best choice.

Against Mephisto:

Blizzard Ice Blast deals 100k dps

63k Light with inifinity, facet in eshhutas, and facet griffins does 100k dps (Ironicly)

Hydra/FB with flickering flame, Phoenix shield, and 2 fire facets does 97.5k dps.

Hydra/FB with infinity and no other - fire res does higher dps vs meph than either cold or light, with or without fire facets.

Against Diablo / Baal (50 fire / light res)

Blizzard/ Ice Blast deals 100k dps

63k Light with infinity, facet in eshutas, and facet griffins does 118k

Hydra/FB with Flickering Flame, Phoenix shield, and 2 fire facets does 128k dps

Hydra/FB with infinity outdamages both light and cold

Bonus: Hydra with 2 facets and a lvl 1 lower res wand charge does 113k dps.

**Summary**

Numbers were obtained by using the character planner at maxroll, but by manually doing the math based on the skill tooltip rather than relying on maxroll's built in calculations (which I don't trust).

The long and short of it is that against bosses, Hydra is certainly viable. At the highest gear levels (infinity) it pulls ahead of other sorc options, and at low gear levels it pulls ahead of blizzard (also at lower gear levels) if you're willing to use a lvl2 lower resist wand on switch.

At the very least, Hydra can be considered a viable boss killer at basically any gear level. It might do even better damage if you use frozen orb instead of fireball, but that's a lot harder to quantify.

It needs to be noted, as well, that it only really matters at higher player counts. On players one, meph gets deleted in under 3 seconds no matter which build you use.

Obviously, Hydra / orb is not going to be as good in most farming areas as lightning. It isn't a great clearing skill in general. But if you are looking for a change of pace for your andy/meph runner you could certainly do a lot worse than Hydra/Orb.

Thanks for reading.

Also good for hardcore players that like to take their time and not die, i.e. not careless people that play recklessly. Hydra deals damage while you are kiting. Very good for bosses like diablo where you have to move.

It is mentioned in the guide, but if on a budget, lower resist wand can be used on bosses and monster packs.

tl dr and horribly spaced/formatted

Yes I know paragraphs with 3-4 sentences in them is not ideal for an internet forum, but the information contained within is accurate and someone may find use out of it :-)

Enjoyed the read and thanks for the info!

thx for your topic. Was thinking about playing a hydra sorc. How is it going for ladder start with lower gear? Does it work as well?

They nerfed the Synergies from 5% to 3% right?

The synergies are indeed 3%, but the math in the original post was done with the 3% values.

If playing solo it does pretty well, it's pretty great for getting through the game, as long as you treat it like meteorb and make sure you max frozen orb asap. That skill carries through nightmare and still holds up in hell.

Hydra isn't great at clearing large groups, but for small packs it is great. It's also nice to be able to cast it and then panic teleport around to evade enemies while it does its work.

The main drawback is that this build is strictly worse at hell meph than a blizzard sorc until higher gear levels. A lower res wand helps out, but its still gonna be a little slower. It's really great at Andariel, though.

It is also better than I thought it'd be in Stony Tomb because the superunique is the only guaranteed cold immune. So whole Hydra isn't wonderful for clearing packs, you still get to use frozen orb in there with Hydra the vast majority of the time.

Overall I'm pretty pleased with it. I respected to Hydra/Orb at 66, so my skill distribution is more optimal, but I think it'd probably work fine with no respec