Fricle

Composed

Middle row

Magic damage

Witches

DPS

Prickly Gatekeeper

Deals AoE Magical Damage to enemies and kills all summoned thorn tendrils. Thorn tendrils that die using this skill deal greater damage.
■ Magical DMG: 630%
■ Minion Death First DMG: 60%
■ Minion Death Second DMG: 120%

Constricting Guard

18 sec Cooldown

Ensnares up to 3 closest enemies with briars, dealing Magical Damage for 5s, and applying Numb Feet and Silence. When the briar is created, summons 1 thorn tendril on the enemy.
Numb Feet: Can't move by walking.
Silence: Unable to use any skills.
■ Magical DMG Per Second: 180%
■ Numb Feet Duration: 5s
■ Silence Duration: 7s

Passive

Increases Outgoing Damage to enemies who are Mad.
■ Outgoing Damage Increase: 84%

Normal ATK

Sends a tracking vine to the enemy and deals Magical Damage.
■ Magical DMG: 75%
Enhance:
At a set chance, summons a thorn tendril.
The thorn tendril attacks nearby enemies until it dies.
When a thorn tendril dies, executes an AoE Attack both ahead and behind.
■ Minion Magical DMG: 15%
■ Minion Death First DMG: 30%
■ Minion Death Second DMG: 60%

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