Apotheosis Cooldown Reduction

Am I crazy or is Apotheosis giving too large of a cooldown reduction, or is my math not right? Is it increased by Haste?..

Apotheosis increases your Holy Word cooldown reduction by 300%. Flash Heal, in this case, reduces the cooldown of Holy Word: Serenity by 6 seconds.

Wouldn’t that be 24 seconds of cooldown reduction?

100%: 12 seconds
200%: 18 seconds
300%: 24 seconds

However, when I cast Apotheosis and do Flash Heal, I only need 2 Flash Heals (28 second reduction) to fully reset Holy Word: Serenity, not 3.

Am I missing something obvious?

Yup you are. The Azerite trait that reduces Serenity’s CD by another 1 second per Flash Heal, and you are also forgetting the cast times of the Flash Heals and the 1 second Global from the Serenity cast. The CD is ticking down during this as well.

Aaaaaaaaahhh, that’s exactly it, I wasn’t even thinking of the Azerite traits for some reason.