Tank Lux is Actually OP in Season 14

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Luxthe Lady of Luminosity

Middle

Rune Page

Precision

Domination

Shards

Flash

Teleport

Starting Items

Early Items

Core Items

Full Build

Situational Items

Doran's Ring

Health Potion

As your R is on a rather short cooldown, look to all in the enemy with a simple QER combo frequently.
Delay a team fight for as long as possible while you keep poking and chipping away at the enemy's health bar.
You can frontline for your team since this build is made to make you into a tank. Don't overestimate yourself though since you can still be killed.

With the Changes to the items this Season, a build that has been quietly OP (until now) is Tank Lux. Yes, you heard it right. This build is meant to make you unkillable while at the same time making sure you deal a lot of damage. The reason why this works on Lux is because she has a lot of damage in her kit so she won't miss any of it even if you go tank.

Early Game: In the early game, Lux should focus on poking enemies with her Lucent Singularity (E) and using her Prismatic Barrier (W) to shield herself from incoming damage. Utilize your Light Binding (Q) to catch enemies out of position, but be mindful of your positioning to avoid ganks.
Mid Game: During the mid game, Lux transitions into a powerful poke and catch mage. Continue poking enemies with your E and use your Q to catch opponents, setting up kills for your team. Prioritize completing Rod of Ages fully and start building your tank items.
Late Game: In the late game, Lux excels in team fights and sieges. Utilize your long-range abilities to poke enemies and zone opponents from objectives. Prioritize protecting your carries with shields and tanking, but also catch enemies with your Q to turn the tide of team fights.