HIGHEST DPS BUILD & RUNES

Its important to note, that in PBE patch 14.1 Perfect Timing has been REMOVED. Instead it has been replaced by TRIPLE TONIC. Moba fire has not been updated with new items and rune changes yet, so I have provided a screenshot of the actual runes & build below.

CHEAT SHEET QUICK SUMMARY
Hwei is a lot simpler than you might realize.
While he DOES have 10 total abilities, you can only use a combination of 3 abilities at most. Most of his abilities serve very niche purposes like mana restore or vision which isn't something you will constantly be using.

Let me help break it down into a really simplified version for you all.

After extensive testing on both PBE and LIVE servers:
Hweis gameplay mainly revolves around his Q abilities
you will rarely use any spells under the W category, and should never use E spells so that you can save it for disengage from ganks or enemies.

Specfically, you will use QE a.k.a: Molten Fissure the most for wave clear and then WE a.k.a: Stirring Lights to restore mana when low. Hwei lacks any sort of kill pressure early is very weak in lane early as well. You need to wait until Level 6 and at least 1 item before you can really kill pressure anyone.

HWEI PASSIVE EXPLAINED:

Abilities apply a Mark that deals bonus damage on the next ability.

HWEI Q EXPLAINED:

Damage and Wave clear abilities. Your Q abilities can be used almost 3 times as often as your other Brush abilities due to its low cooldown

Q sub-abilities

QQ

Devastating Fire

Long range skill shot that explodes with an AOE after it hits an enemy or minion. (good for poke/chip damage, CAN BE BLOCKED BY MINIONS)

QW

Severing Bolt

Exact same ability as Dark Matter only Hwei's barely deals any damage unless the enemy has been Crowd Controled (rarely worth using)

QE

Molten Fissure

Massive AOE roll out that stays on the ground and deals damage over time (probably hweis best ability)

HWEI W EXPLAINED:

UTILITY a.k.a supportive abilities. I've found that ALL Abilities in this category, will rarely ever get used in your games. Its better to save mana to poke with your other abilities as Hweis mana costs are really high. Only fall back on these spells when necessary, for example, when you are low on mana in lane or teamfighting.

W sub-abilities

WQ

Fleeting Current

Aoe Rollout can be instant casted while moving, grants movespeed and a small bonus of ability power to all who stand ontop of it

WW

Pool of Reflection

AOE cast on floor, grants you & allies a small shield that grows larger in HP over time

WE

Stirring Lights

Grants bonus damage on Hweis next 3 attacks or spells and restores a small amount of mana.

HWEI E EXPLAINED:

CROWD CONTROL ABILITIES. Used to disengage, do not try to use these to start a fight ever.

E sub-abilities

EQ

Grim Visage

Skill shot, single target, fear. Very good for disenage, one of Hweis best abilities. (CAN BE BLOCKED BY MINIONS)

EW

Gaze of the Abyss

Can only target champions, grants vision and roots enemies that stay inside it. Very short range and likely not worth using almost ever.

EE

Crushing Maw

Rectangle AOE that pulls enemies and minions to the center of itself when hit and slows after (very situational)

HWEI R EXPLAINED:

Skill shot ultimate that sticks to enemies and grows larger in AOE over time, slowing enemies and dealing a huge damage chunk at the end. This ability applies a slow that becomes stronger over time, so its usually good to use your ultimate first as an opener, then secure landing the rest of your combos.