New to 5E (but played AD&D 1E many moons ago) and have a question about Tempest Cleric. At 8th level you can add 1d8 thunder damage to a melee attack (Divine Strike). If you crit and do 2d8 instead since you roll the extra dice, can you use your channel divinity: Destructive Wrath to maximize the damage to 16pts thunder damage even though you are technically not rolling dice anymore.

Still learning the rules so wanted to ask.

You would do the 16 damage, here's the order of operations:

1. You make an attack and crit
2. You decide to apply your Divine Strike (which is added to the attack after you hit)
3. Because Divine Strike damage is added to the attack roll, it benefits from being a crit, so becomes 2d8
4. Because it's thunder damage, you can apply Destructive Wrath, which lets you "deal maximum damage, instead of rolling"
5. You do 16 damage rather than rolling 2d8

Thanks