Lux can scout, zone, peel and shield - all on low CD with high damage.

• - [P] - Great damage! Detonates spellthief's stacks.
• - [Q] - Legendary 2sec-double-target-snare! 6sec CD... The peels :D
• - [W] - Top AOE shield! This is the reason for support Lux!
• - [E] - Awesome scouting and zone control! Don't detonate it.
• - [R] - The finisher! Stealing, scouting, showing off ;)

Push and spamm Prismatic Barrier with Locket of the Iron Solari (MR), Ardent Censer (On-Hit + AS), Windspeaker's Blessing (+10% + Armor + MR), Runic Armor (+8%) and 45% CDR.
Let foes struggle through Light Bindings and Lucent Singularitys.
Her Combo hurts without AP, too: + AA + + + + + AA + = 1662 + 265% AP

Early Game - Invades / Jungle Start / Lane Start

To take advantage of her shield, a close-up combat style is needed. Make sure to beef up her resiliance with runes and masteries (0/18/12). Rush CDR and the neccessary MReg and provide early HP and resistance items. Starting with Binding or Singularity leaves you vulnerable. Kill potential is low. Play save with shield for your jungler and early poke, especially from melee all-in opponents. Play passive.

Mid Game - Lane / Recall / Roam

Roam and ward the map. Scout with your E and surprise gank with your pain. Your shield makes you deceptivly tanky if you tailor resistances to your enemies. Take advantage of enemy dives and tank dps with it (e.g. dragon).

End Game - Warding / Objectives / Teamfights

Hit your entire team with locket and Prismatic Barrier in teamfights. Peel for your carry and finish off fleeing enemies with your ult. Your scouting with blue trinket, singularity and even ult provides valuable map information.

Thank you for your attention!