Season 15 has changed the levelling conversation. Kurast Undercity still has value, but it is no longer the only serious option. A properly prepared Helltide run can push seasonal characters through Paragon levels at a far steadier pace, especially when you use the right D4 items and keep the group moving. The trick is not one single bonus. It is the way several small advantages fit together.

Build the experience setup first

Start with a Nightmare Dungeon Sigil carrying the Forgotten Wisdom affix. Completing that dungeon guarantees an Experience Well, and the well grants a one-hour increase of fifteen percent to experience gained. Do not activate it and then wander around town. Get your party together first, sort your gear, and head straight towards the Helltide zone. Group play adds another experience boost, while a clean route prevents the buff from being wasted.

Source   Useful effect   How to use it   
Experience Well   Fifteen percent experience   Activate before the farming session   
Group play   Extra experience from shared kills   Stay close and rotate between packs   
Shard of Damnation   Conditional experience increase   Keep pressure on elite groups   
Shard of Lies   Bonus value under health conditions   Maintain the required combat state   

Turn Helltide into a dense killing route

The War Plans setup is where the method starts to pull away from ordinary farming. Put points into the Helltide branch, then take Hellmouth to add maggot-spawning Hellworms. Wretched Vermin brings in demonic rats, and the red Shard of Terror upgrades those rats into elite enemies. That change matters more than it first appears. You get extra targets, more experience drops, and a healthier supply of Anomaly Gore without stopping to search for separate packs.

Take the Helltide nodes that increase enemy density.
Use the Shard of Terror with Wretched Vermin for reliable elite spawns.
Activate Chaos Rifts when nearby events can be combined.

Raise the difficulty without slowing down

Choose the Heralds node to lift monster power by one. The Brothers in Flesh node can call in the Butcher and reward Profane Mindcages. Use one, then two, and then three during a committed session if your build can handle the pressure. Each extra level makes the enemies tougher, but the experience per kill rises with it. The Shard of Terror also extends shrine time by fifteen seconds and grants fifty percent movement speed, so you can cross the zone quickly rather than waiting for every pack to appear.

Follow the events and cash out the rewards

Chaos Rifts should be your main targets. They keep elite enemies arriving, and two rifts close together can create a remarkably busy fight. Treasure Goblins may open further rifts, giving a good run an unexpected second wind. When the session ends, return to town and spend the Season Reputation at the Season Board. The reward caches add experience, useful equipment, and summoning materials for Uber Boss encounters. With sensible route planning and buy cheap D4 items when your build needs a missing upgrade, this Helltide loop supports both fast levelling and strong endgame preparation.