Eden’s Promise: Eternity (Savage) - Door Boss
In order to keep full uptime during Diamond Dust, you should use your melee combo to your advantage.
At 2.5 GCD, you should start your melee combo immediately after the Diamond Dust cast ends. Doing so will have your Scorch line up with the appearance of the ice floor, allowing you to use Scorch before sliding to keep your GCD rolling. You can then perform a Dualcast combo, sliding into place after your instant cast.
If you need to slide a second time, a Swiftcast can be used here as well. Manafication can be used on cooldown here to keep uptime during icicles.
When your four minute Manafication comes up, you may already be very close to a regular combo. If you are above ~65 | 65 Black and White mana, you can consider holding this Manafication.
This will affect your combo timings during Lions later in the fight, so it may be worthwhile to try both and see which lines up better with your group’s strategy.
Potion And Double Melee Timings
Your second potion will be using either during or after the Lions mechanic. If you’re not already pushing enrage, your group may want to hold buffs until after lions.
Despite this, you may have to do your first melee combo if you do not want to overcap during the mechanic. In this scenario, you can use your potion and do your first melee combo during Lions, and use your Manafication combo along with Embolden after the mechanic ends.