Level 90 Whirling Slash Ritualist^0.2

Notes

estimated cost: 10d ~ 120d
the build works great even without Astramentis Stellar Amulet.(I tested)
If you want cheaper version, get rid of Headhunter and Stellar Amulet. It'll still work very fine.(Detailed explanation below)

You use 2 Whirling Slash. Main one and 2nd one.
lower level is better for 2nd one, but it's not that important. Honestly almost no difference, since you're gonna use it only a few times while mapping.(or even just 1 time at the start)

Use 2nd Whirling Slash when you start mapping, and then, just spam the main one.
If you happen to leave the area of vortex, you'll need to remake vortex again with the 2nd one.
Use mana flask when there's no enemies around you. Without enemies, it'll be harder to sustain mana.

---gears

Spear: Attack Speed is neccessary. Dexterity feels good to have. get ones with highest DPS. Physical or elemental, doesn't matter that much honestly(ele slightly better).

Helm: Get ones with more than 15% increased attributes. They're affordable. But if you're out of budget, prioritize Dexterity and Intelligence.

Rings: Prioritize attributes. All Attributes = Dexterity > Intelligence. Get as much as flat damage too if you have enough budget.

Amulet: Get Astramentis Stellar Amulet. If you don't have money, get rare one. it'll decrease your DPS, but the build still works very fine. I tested it.
If you decided to use Rare amulet, aim for [Rarity, Max life, Spirit, Attributes, Resistance, Melee skill, Mana regen], whatever you want.

Howa: Get one with 1 to '12' Lightning Damage to Attacks per 20 intelligence. They're pretty affordable

Boots: Get one with 3 Elemental Resistance. again, if you have enough budge, aim for maximum life too. But you don't need move speed at all.

Headhunter: Aim for ones with more attributes. Again, prioritize Dexterity over Strength. You can use other Belts too if you're out of budget.

Flask: Honestly You don't even need unique flask, it makes only tiny difference I believe.

Charms: Get anything you want, But I recommend you at least using freeze charm.
If you're a baller, you can add 'Rite of Passage' and 'The Fall of the Axe' charm. I haven't tried myself, but I think They're gonna perform incredible with this build.

Jewels: Aim for #% mana on kill, #% life on kill, and increased area of effect.
trade link: https://www.pathofexile.com/trade2/search/poe2/Dawn%20of%20the%20Hunt/BjzeZlkC8

If you're lucky, you'll be able to find juicy Megalomaniac jewel on the market.
trade link: https://www.pathofexile.com/trade2/search/poe2/Dawn%20of%20the%20Hunt/anOaJjpCe
it's not mandatory, but feels better to have one.
Btw I might have missed some good nodes in the trade link. you can check them out and add yourself too.

---Gems

'Volcanic Erption' Support Gem isn't needed. I used it because I thought it'd be cool to add a bit more effect lol since I had enough DPS.
You can use 'Elemental Focus' instead. I didn't test it but maybe you can still inflict elemental ailments even with elemental focus gem. since your vortex is from 2nd whirling slash. lol

For the 2nd whirling slash, if you don't have enough money for Perfect Jeweller's orb, get rid of 'magnified effect'.