Deathfire Grasp 3128since 0.151.2 16 changes removed in 10.23.1
3100g (680g base, 2170g sell)
Active — UNIQUE Active: Deals 15% of target champion's maximum Health in magic damage and increases all subsequent magic damage taken by the target by 20% for 4 seconds (60 second cooldown).
Builds from: 
Needlessly Large Rod
Fiendish Codex
SPELLDAMAGECOOLDOWNREDUCTIONACTIVE
Click any two patches to compare; the current range is shaded.
− Deal magic damage equal to 15% of the Target's Max Health, and then amplify damage they take by 15% for 4 seconds (90s ).
+ Deal magic damage equal to 15% of the Target's Max Health, and then amplify damage they take by 15% for 4 seconds (90(0s cooldown)).
− Deal magic damage equal to 15% of the Target's Max Health, and then amplify damage they take by 15% for 4 seconds (90(0s cooldown)).
+ Deal magic damage equal to 15% of the Target's Max Health, and then amplify damage they take by 15% for 4 seconds (90(0s)).