Mayo

Madness

Back row

Physical damage

Sprites

DPS Tier 3

Collector's Creed

Shoots a poisoned needle at the enemy with the highest Attack, dealing Physical Damage 3 times and applies Poison:
Poison: Applies Damage every second and reduces Damage dealt.
■ Total Physical DMG: 118.8%
■ Poison Duration: 4s

That Collectible Is Mine, IMHO

11 sec Cooldown

Shoots a poisoned needle at a random enemy, dealing Physical Damage 8 times and applies Poison.
Poison: Applies Damage every second and reduces Damage dealt.
■ Total Physical DMG: 140%
■ Poison Duration: 4s

Passive

Increases Enhanced Attack Damage.
Deals additional Physical Damage each time the duration of Poison caused by Mayo's skill ends.
Poison: Applies Damage every second and reduces Damage dealt.
■ Enhanced ATK DMG Increase: 24%
■ Additional Physical DMG: 25%

Normal ATK

Shoots a blowgun dart, dealing Physical Damage to the enemy.
■ Physical DMG: 100%
Enhance:
At a set chance, shoots a poisoned dart, dealing Physical Damage to a random enemy and applying Poison.
Poison: Applies Damage every second and reduces Damage dealt.
■ Physical DMG: 125%
■ Posion Duration: 2s

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