Entry Hazards

Entry Hazard Change:
No Entry Hazard is permanently set anymore
This lessens the need for hazard removal on a team, but does not necessarily mean that defog/rapid spin/mortal spin are less useful.

Spikes:
Still up to 3 layers, but every time a mon is affected by spikes, a layer is removed. Meaning if 3 layers are up, after 3 switch ins, there are no more spikes on that side of the field. They can be re-set at anytime though.
Reasoning:
Spikes have always been visually comparative to road spikes that get stuck in tires, so in theory they should get stuck in whoever touches them, thus removing 1 layer every switch. Balance-wise spikes are one of the best hazards as of now, as they do a flat 25% to anything touching the ground, while most things that would take 25% from stealth rocks are wearing HDB, making rocks much weaker since their introduction in gen8.

Stealth Rock:
Lasts 5 turns. Effect is unchanged.
Reasoning:
Rocks have been a controversial hazard since their introduction, as nothing could avoid the chip damage it deals outside of having Magic Guard (or Mountaineer if you play CAP). HDB brought many of the SR weak types into the fold because of how powerful they were. Making them time based though gives a secondary option of stalling out the rocks and then bringing something weak to rocks in. It also makes the strategy of immediately setting up rocks a lot less effective unless the team style requires it (HO to break focus sashes or shuffling moves like Roar).

Toxic Spikes:
Still up to 2 layers, but like regular spikes, a layer is removed every time a mon is affected by them. Grounded Poison types still absorb them. Grounded steel types do not have any effect on the spikes laid out unless the active opponent has Corrosion.
Reasoning:
The same as spikes, however T-Spikes are incredibly overpowered and need something cutting their strength. They can easily destroy a team structure without much skill involved, as they punish rapid spinners without HDB not named Iron Treads and Forretress (and I guess Delibird...) with at least a poison status if they don't switch immediately in before the hazards are set up. Corrosion gets a small buff though, being able to poison with TSpikes when they're on the field.

Sticky Web:
Breaks after 1 mon is affected by them. Hazard removal does not work on it.
Reasoning:
Sticky web is ridiculously overpowered as it quite literally ruins any team style not named trick room. Even stall doesn't want to deal with webs. Given this is intended to be a spider web, it is easily broken. However, because spider webs are resilient, hazard removal does not do anything to it.

--New Hazards--
Riptide - Water
Lasts 3 turns. Prevents any grounded non-water types from switching.

Vortex - Flying
Lasts 3 turns. Prevents any non-grounded Pokemon from switching.

Hotspot - Fire
1 layer, burns any grounded non-fire type and breaks. Grounded fire-types absorb it.

Telekinesis - Psychic
[New Effect]
Lasts 3 turns. Reduces evasion of targets by 1 stage. Flying types and Levitate users have evasion reduced by 2 stages.
Unlike gravity, it only affects targets side.

Tangle - Grass
Up to 2 layers. First layer reduces target's speed by 1 stage, second layer prevents switching. Breaks after 1 mon is affected by them (as in entirely). Affects non-grounded targets. Fire attacks burn it away and remove the speed debuff. Hazard removal does not work on it.
Ex: Cinderace switches into Tangle, cannot switch and suffers Speed -1. Cinderace uses Pyro Ball, Tangle is removed and Cinderace regains its speed.

Shocktrap - Elec
1 layer, paralyzes any grounded non-electric type and breaks. Electric types absorb it (even non-grounded ones).

--New Hazard Removal--
Spinout - Steel
[New Effect]
Steel-type Rapid Spin.

--New Effects--
Whirlpool
Now sets Riptide. Still deals damage over time.

Magma Storm
Now sets Hot Spot. Still deals damage over time, but no longer traps.

Fire Spin
Now Sets Vortex. Still deals damage over time, but no longer traps grounded targets.