Hollow Radiance 6664since 10.23.1 20 changes
2800g (1050g base, 1960g sell)
Refuel: Moving and taking damage from Champions and large monsters fills up the Chemtank. At 100 stacks, your next basic attack deals 40-120 (+1% max Health, + 3% Move Speed) magic damage to all nearby enemies (increased by 30% against minions and 200% against jungle monsters).Mythic Passive: Grants all other Legendary items 5 Ability Haste and 50 Health.
Active — Active -:
Active — Supercharged: Grants 40% Move Speed towards enemies or enemy turrets for 4 seconds. Once near an enemy (or after 4 seconds) a shockwave is emitted that Slows nearby champions by 50% for 1.5 seconds (90s cooldown).
Builds from: 
Bami's Cinder
Null-Magic Mantle
Cloth Armor
Builds into: 
Rabadon's Deathcrown
HealthSpellBlockArmorAuraActiveCooldownReductionSlowNonbootsMovementTenacityAbilityHaste
Click any two patches to compare; the current range is shaded.
− Taking or dealing damage causes you to begin dealing 0 magic damage per second to nearby enemies (increased by 25% against minions) for 3 seconds.
+ Taking or dealing damage causes you to begin dealing magic damage to nearby enemies.
− Killing an enemy deals 0 magic damage in an area around them.
+ Killing an enemy deals magic damage in an area around them.
− Killing an enemy deals magic damage in an area around them.
+ Killing an enemy deals magic damage around them.
− Taking or dealing damage causes you to begin dealing magic damage to nearby enemies.
+ After taking or dealing damage, deal magic damage per second to nearby enemies for 3 seconds.