Transformative reactions cannot crit and scale only on Elemental Mastery and character level. They are effected by elemental resistance to the type of damage the reaction deals.
Shatter, Superconduct, and Swirl have internal cooldowns and can only deal damage twice within the span of 0.5 seconds. Overload can only deal damage once every 0.5 seconds.
Overload is an elemental reaction triggered by applying Pyro on a target already afflicted by an Electro aura or vice versa. Overload will cause an explosion of Pyro damage to occur that will destroy Geo shields quickly. Triggering Overload in an AoE will only cause one instance of Overload damage.
You can trigger Overload on electrocuted bodies of water.
Overload has a reaction specific ICD of 0.5 sec where enemies overloaded or hit by the aoe caused by an overload procced by one character are then immune to the damage caused by overload procced by that character for 0.5 seconds. They still suffer gauge reduction and stagger, even without taking damage.
Superconduct is an elemental reaction triggered by applying Electro on a target already afflicted by a Cryo aura or vice versa. Superconduct reduces an enemy's physical damage resistance by 40% by 12 seconds. Triggering Superconduct in an AoE will only cause one instance of Superconduct damage.
Electro-Charged is a special Transformative reaction that breaks the normal convention of “one elemental aura on an enemy at a time." When an enemy is Electro-Charged, both the Hydro and Electro aura lies underneath the Electro-Charged status. It follows that when applying a third element, like Pyro, you can trigger both Vaporize and Overload in the same damage instance. Electro-Charged continues to tick every second until there is 0.5 seconds worth of Electro and Hydro aura remaining. For a more detailed description of Electro-Charged, refer to the Evidence Vault.
Electro-Charged can be extended by hitlag, presumably by extending the aura duration.
Electro-Charged can spread to nearby targets if they have a Hydro aura, however, the chain lightning will trigger Electro-Charged damage without applying an elemental aura.
Electro-Charged, in combination with Heavy Hits, can stun a ruin guard similar to using an aimed shot on their weakpoint.
This is because both Electro-Charged and Heavy Hits deal a substantial amount of poise damage
For more details on poise, we have a page dedicated to it
Blunt attacks (such as Claymores, Geo, Klee's bombs, etc) will apply Shatter on Frozen targets before any Elemental damage is dealt, preventing you from Melting or Vaporizing. Attacks that apply Shatter have different GU values, refer to the Evidence Vault for extended reading on Shatter GU by Bobrokrot.
Frozen is an elemental reaction triggered by applying Cryo on a target already afflicted by a Hydro aura or vice versa. If the Frozen aura expires or is Shattered, any underlying Hydro or Cryo aura will persist, note that the Cryo or Hydro application to trigger Frozen will consume the appropriate amount of aura.
Applying a 2U Hydro -> 1U Cryo aura will cause the enemy to be affected by both frozen and hydro. However, applying a 1U Cryo -> 2U Hydro will only cause the enemy to be affected by frozen.
Additionally, one reaction occurs at a time, if you apply Pyro to a Frozen aura that has an underlying Hydro aura, only the Melt occurs. If the underlying aura is Cryo, Cryo can Melt, so the Melt will reduce both the Freeze and the original Cryo aura. Some reactions effect both, others only effect one.
The order of elements applied and the gauge strength determines if a second reaction occurs and what reaction it is, whenever a blunt elemental attack is used against a frozen target.
The duration of Freeze is dependent on the lowest gauge element when it is triggered, regardless of their order. It scales non-linearly with the aura strength of Hydro and Cryo.
The behavior of Freeze curves to give diminishing returns at higher GU values. This curve predicts a duration of about 5.7s for 2U.
Swirl is an elemental reaction triggered by applying Anemo to a target already affected by Hydro, Pyro, Cryo, or Electro. Swirl will cause AoE elemental damage of the same type as the original aura, spreading that element to affected targets which can trigger additional reactions. Triggering Swirl in an AoE can cause up to two instances of Swirl damage per element for each enemy in the AoE. Note that this constraint does not include the Anemo hit or any damage dealt by reactions caused from the swirls, so it is possible to have more than eight total damage instances per target.
In the special case of Hydro, only the target afflicted with the Hydro initially will take damage as the dispersion of hydro will not harm enemies.
All reactions caused by swirling auras together use the stats of the character that triggered the swirl in their damage calculation.
If an amp reaction is triggered in this manner, the damage will snapshot EM and the Base Hit will be the Swirl damage number.
Environmental element sources (such as campfires and burning grass) can be swirled.
Swirl is an separate effect from Elemental Absorption.
When a Swirl reaction occurs and the AOE effect of the swirl reaction meets another enemy with an aura, the swirled element will cause a reaction with that aura. This reaction will use the Anemo user's Character Level and Elemental Mastery to determine damage (if applicable). The subsequent reactions work in the same way that normal reactions do.
It is possible to simultaneously trigger two swirls on one target from the same Anemo hit if the target has two swirl-applicable auras, such as an Electro-Charged enemy or a Frozen enemy with an underlying Hydro aura. This double swirl can only occur when the gauge reduction from the Anemo hit is greater than the Electro gauge (in the case of EC) or the Hydro gauge (in Frozen/Hydro). If this condition is not met, the anemo attack will only swirl Electro (for EC) or Hydro (for Freeze/Hydro).
More detailed guides on Swirl:
Swirl Guide by Terrapin#8603 (added 4/30/2021)
Crystallize is an elemental reaction triggered by applying Geo on a target afflicted by Pyro/Hydro/Cryo/Electro that creates a shard of the given element. Picking up the shard grants a shield of the shard's element. Crystallize deals no damage, and instead the base health of the shield generated scales on Elemental Mastery and character level of the character that triggered the Crystallize reaction.
Triggering Crystallize on an Electro-Charged target will provide an Electro Crystal.
Picking up multiple crystals refreshes the duration of the shield and its element type.