Elena

Composed

Middle row

Physical damage

Elves

DPS

Tactical Drone MK-2

Emits a pulse wave forward, deals AoE Physical Damage to enemies, and applies the Electrocution debuff.
Electrocution: Reduces Attack Speed and Movement Speed.
■ Physical DMG: 1260%
■ Electrocution Duration: 4s

Codename D-CAT

Sends a special drone out that emits a pulse wave, and deals AoE Physical Damage to enemies 8 times.
■ Physical DMG: 1470%
■ Final Explosive Physical DMG: 630%

Passive

If Amelia is deployed in the Line-up, reduces Incoming Damage.
■ Incoming DMG Reduction: 46%

Normal ATK

Basic:
Shoots an energy sphere and deals damage to the enemy. The final hit deals greater damage.
■ Physical DMG: 90%
■ Final Hit Physical DMG: 60%
Enhance:
At a set chance, fires an overcharged energy sphere, dealing Damage to the enemy.
■ Physical DMG: 600%

Skill priority

You will level up most skills regardless how useful they are for the combat power padding in endgame. As a general rule of thumb:

Units you are not sure you will use long term: Skills to level 4. If they're passives that benefit the team, can take that to 7.
Strong units but not your main personality: Skills to level 7 for raids and elemental content. Not worth going higher if they are not your main team.
Strong units on your main personality (and waifus): Max out skills. You can start with 7/7/7 and slowly work towards 12/12/12 when you can sweep stage 10.

Recommended artifacts

Artifacts and runes will always change depending on the stage and content you are currently facing, this is just a couple of examples on what items work for this Apostle.

Legendary