Blade Vortex

Blade Vortex is a spell that creates an ethereal blade that spins around the caster that deals physical damage, each blade lasting for the minimum duration of 5 seconds.

Skill Functions and Interactions

Physical Damage: Because Blade Vortex deals physical damage, it can be boosted by supports and skills that are more commonly used to modify attacks, such as the support gem and the Hatred aura.

Spell Damage: Despite the fact that it does physical damage, Blade Vortex is a spell and not an attack. It does not utilize weapon damage in any way. Blade Vortex is one of three skills that work in this manner, the other two being and . Its damage can be amplified by Spell Damage on items and passives from the skill tree, as well as support gems that increase spell damage.

Leech: Leech effects that apply to Spell damage and to damage types dealt by Blade Vortex (Physical by default) will work as usual. Note that leech effects which apply to attacks do not apply to Blade Vortex because it is a spell, not an attack.

Area of Effect: Due to the fact that Blade Vortex has the AoE tag, increases and decreases in AoE will augment the radius in which the skill deals damage (e.g. , and ).

Duration: Because of the duration nature of this skill, it is possible to have multiple blades active at the same time, up to a maximum of 50 blades. Once the limit is reached, creating a new blade will simply remove the oldest existing active blade, similar to .

Visual effect: Blade vortex's visual effect does not scale with Area of effect modifiers. Instead, to give a rough indication of radius, there are several versions of the knife effect, each rotating at a different radius. The skill will always try to have one knife using the largest-radius effect that's not larger than the actual radius of the skill, but that skill results in discrete visual changes where you need to reach a certain threshold before the next wider effect can be used. The full radius is always used mechanically.

Gem level progression

Level			Mana Cost	Physical Damage	Exp.	Total Exp.
1	12	33	6	N/A	0	0
2	15	39	6	N/A	15249	15249
3	19	48	7	N/A	41517	56766
4	23	56	8	N/A	81983	138749
5	27	64	9	N/A	147968	286717
6	31	73	9	N/A	250557	537274
7	35	81	10	N/A	405086	942360
8	38	88	11	N/A	447718	1390078
9	41	94	11	N/A	615318	2005396
10	44	100	12	N/A	834639	2840035
11	47	106	12	N/A	1570760	4410795
12	50	113	13	N/A	1633987	6044782
13	53	119	13	N/A	2151030	8195812
14	56	125	14	N/A	2812189	11008001
15	59	132	14	N/A	5099360	16107361
16	62	138	15	N/A	9400731	25508092
17	64	142	15	N/A	15273366	40781458
18	66	146	16	N/A	26286582	67068040
19	68	151	16	N/A	62890590	129958630
20	70	155	16	N/A	212046017	342004647
21	72	159	17	N/A	N/A	N/A
22	74	N/A	17	N/A	N/A	N/A
23	76	N/A	18	N/A	N/A	N/A
24	78	N/A	18	N/A	N/A	N/A
25	80	N/A	18	N/A	N/A	N/A
26	82	N/A	19	N/A	N/A	N/A
27	84	N/A	19	N/A	N/A	N/A
28	86	N/A	19	N/A	N/A	N/A
29	88	N/A	20	N/A	N/A	N/A
30	90	N/A	20	N/A	N/A	N/A
31	91	N/A	20	N/A	N/A	N/A
32	92	N/A	20	N/A	N/A	N/A
33	93	N/A	21	N/A	N/A	N/A
34	94	N/A	21	N/A	N/A	N/A
35	95	N/A	21	N/A	N/A	N/A
36	96	N/A	21	N/A	N/A	N/A
37	97	N/A	21	N/A	N/A	N/A
38	98	N/A	22	N/A	N/A	N/A
39	99	N/A	22	N/A	N/A	N/A
40	100	N/A	22	N/A	N/A	N/A

Calculating Sustained DPS

Blade Vortex's in-game tooltip DPS gives the average damage of one hit from one Blade Vortex instance, multiplied by casts per second. This value is misleading primarily because each Blade Vortex instance can hit more than once over its duration. Calculations of sustained Blade Vortex DPS during continual casting must account for the number of times each Blade Vortex instance hits over its duration, and the hard cap of 50 on number of Blade Vortex instances. Two different formulas for sustained DPS during continual casting follow.

If fewer than 50 instances can be maintained

[Sustained DPS] = [tooltip DPS] * [Blade Vortex duration] * 1

Explanation

[Sustained DPS] = [average damage of one hit from one instance] * [casts per second] * [Blade Vortex instance duration] * [hits per second]
[Tooltip DPS] = [average damage of one hit from one instance] * [casts per second]
⇒ [Sustained DPS] = [Tooltip DPS] * [Blade Vortex instance duration] * [hits per second]

Blade Vortex hits at a fixed rate of 1 hit per second regardless of cast speed. We substitute that value to get the final formula.

[Sustained DPS] = [tooltip DPS] * [Blade Vortex duration] * 1

If 50 instances can be maintained

[Sustained DPS] = [tooltip DPS] / [casts per second] * 50

Explanation

Blade Vortex's tooltip does not account for the 50 instance limit. When the maximum limit of 50 Blade Vortex instances can be maintained, sustained DPS can be given by the average damage of one hit from one Blade Vortex instance, multiplied by the number of instances and the number of hits per second.

[Sustained DPS] = [average damage of one hit from one instance] * [number of instances] * [hits per second]

We know that the number of instances is 50 in this scenario, and the hits per second is always 1. That leaves one value for us to find: average damage of one hit from one Blade Vortex instance. We calculate this value using what we know about the in-game tooltip's DPS value.

[Tooltip DPS] = [average damage of one hit from one instance] * [casts per second]
⇒ [Average damage of one hit from one instance] = [tooltip DPS] / [casts per second]

Substituting our calculated values into the original formula gives a final formula for sustained DPS at 50 Blade Vortex instances.

[Sustained DPS] = [tooltip DPS] / [casts per second] * [number of instances * [hits per second]
⇒ [Sustained DPS] = [tooltip DPS] / [casts per second] * 50 * 1
⇒ [Sustained DPS] = [tooltip DPS] / [casts per second] * 50

Alternate skill effects

Name	Cost	Description
Demonic Blade VortexDemonic Blade VortexSkill Gem EffectYour Blade Vortex becomes a black and red demonic vortex.	90	Replaces the standard effect on a skill gem with a black and red demonic vortex. Preview

Version history

Version	Changes
2.2.0	The frequency with which Blade Vortex's can repeatedly hit the same enemy has been halved, but its damage and damage effectiveness have been doubled.
2.1.1b	Extra Gore now doesn't trigger every time Blade Vortex hits. Fixed a bug where some of the visual effects on Blade Vortex weren't being updated when swapping in and out support gems which modified the area of effect. Fixed a bug where some of the effects of Blade Vortex weren't finishing their animations smoothly.
2.1.0	Added to the game.