Normal Attack
Thunderwave
Stats:

Thunder
CD: -
Swings Mjölnir to attack the enemy continuously, dealing Thunder DMG equal to 926.6% ATK in total. Following up its derivative skill with a normal attack will start the normal attack from the fourth strike and grants Unyielding for 2s during the follow-up.
Passive:
Every hit landed with a normal attack or skill attack grants Thundercloud points, which can stack up to 100. 7 Thundercloud are expended every 0.5s. Gains 9 Thundercloud for each normal attack hit and 15 Thundercloud for each skill hit, and gains 15 more Thundercloud for each skill hit in Thunder Frenzy state. Every 1 point of Thundercloud increases Independent DMG dealt by 0.3%, with the effect maxed out when Thundercloud is at 80.
Enters Thunder Frenzy state for 2s when casting a derivative skill, with effect duration extended by 0.01s for every 1 point of Thundercloud owned (up to an extension of 1s).
Thunder Frenzy: Becomes Invincible for a short time upon entering the state. Thundercloud will not be automatically expended during this state, and Mod deals 15% more Thunder DMG.
Traces: Gains 1 Trace when a hit is landed with the fifth strike of a normal attack.
Skill 1
Quivers Underground
Stats:

Thunder
CD: 9s
Rushes toward the enemy with Mjölnir in hand, dealing Thunder DMG equal to 598.9% ATK in total. For a short time after skill cast, skill is replaced by the derivative skill: Hammerstrike, which can only be cast as a follow-up to Quivers Underground.
Hammerstrike: Attacks surrounding enemies with Mjölnir, expending 3 Traces to deal Thunder DMG equal to 1123% ATK in total.
Traces: Gains 1 Trace when a hit is landed with Quivers Underground.
Stats:

Thunder
CD: 12s
Swings Mjölnir wildly, pulling in nearby enemies for a short time and dealing Thunder DMG equal to 898.4% ATK in total. Within a short time after skill cast, this skill will be replaced by the derivative skill: Rumblestrike, which can only be cast as a follow-up to Rumbles Faraway.
Rumblestrike: Spins Mjölnir and then smashes it into the ground, expending 3 Traces to deal Thunder DMG equal to 1590.9% ATK in total.
Traces: Gains 1 Trace when a hit is landed with Rumbles Faraway.
Skill 3
Trembles Deep Within
Stats:

Thunder
CD: 15s
Swings Mjölnir, then smashes it into the ground, dealing Thunder DMG equal to 1123.1% ATK in total. Within a short time after skill cast, this skill will be replaced by the derivative skill: Tremblestrike, which can only be cast as a follow-up to Trembles Deep Within.
Tremblestrike: Swings Mjölnir and smashes it into the ground again, expending 3 Traces to deal Thunder DMG equal to 1880.9% ATK in total.
Traces: Gains 1 Trace when a hit is landed with Trembles Deep Within.
Ultimate Skill
Fury at Twilight
Stats:

Thunder
CD: 20s
Summons the Járngreipr gloves that unleash the power of raging thunder, and also enters Thunder Rage state. Skill cast grants all Trace Mods on the team a 30% Skill DMG boost for 12s.
Thunder Rage: Grants Control Immunity and DMG Immunity, though Mod may not move or cast skills or Dodge. Thundercloud buffs are raised to max. Expends all Thundercloud with no further automatic expenditure, then grants 7 Thundercloud every 0.2s thereafter. Keep tapping the attack button to keep casting skill attacks with Járngreipr which deal Thunder DMG equal to 758% ATK in total. The second strike of the attack also sends down five thunderbolts in front, with each dealing Thunder DMG equal to 50.5% ATK. Unleashes one last fist attack automatically when Thundercloud is at max, dealing Thunder DMG equal to 1871.8% ATK, then exits Thunder Rage state immediately after.
Gains a 4% Ultimate Skill charge for each Trace expended by the Mod or a teammate.
Stats:

Thunder
CD: -
Quickly dodges the enemy's attacks and can Dodge two consecutive times. Extremity Dodge triggers the Dodge effect. Following up an Extremity Dodge with a normal attack will start the normal attack from the fourth strike and grants Unyielding for 2s. Gains 15 Thundercloud points.
Dodge effect: Entering Zero Time significantly slows all enemy movements for 3s. Dodge effect can trigger once every 20 seconds.
TODO: add tooltip like ingame