Knight Castigator and House Terryn plates.

[The Emperor]

What are you talking about? It clearly says that Tempest Attack is taken instead of normal attacks, and Deflagrate only works on unsaved wounds caused by normal attacks.

Or if you want a complicated word play version: Deflagrate happens after normal attacks are resolved (which is I4 step). At this point there would be no wounds inflicted for Deflagrate to work with, so nothing happens. You then do Tempest Attack at I2, but you don't do Deflagrate, as that happened with normal attacks (Deflagrate is called out as not a normal attack).

Exactly. Deflagrate is triggered by normal attacks, but when you make a Tempest Attack you're not making normal attacks, as it's specifically called out as not being a normal attack. It's the very first sentence under Tempest Attack. "Rather than attacking normally..." There's a reason that rule is worded in that way, while Deflagrate includes the wording "After normal attacks...". Both abilities aren't intended to be used together. The only way to activate Deflagrate is to make your 4 regular Attacks at Initiative 4.

[DWest]

So what you're trying to say is if the Knight should charge through difficult terrain, it no longer gets to use Deflagrate, as we're no longer attacking at I4? That's ridiculous and you know it. Here's an easy test: Replace the word "normal" in the Deflagrate rule with "initial". Does the wording still make sense? The answer is yes, which means the word "normal" doesn't need to be there.

Again, the fact that Tempest Attack says "use the weapon's profile" is another clear indicator that Deflagrate is activated. Any time a model is given a special attack that doesn't use their weapon abilities (see Hammer of Wrath and Gabriel Seth's special ability for examples), it specifically indicates "do not use the weapon profile or model special rules, only this base profile".

[Gir]

So what you're trying to say is if the Knight should charge through difficult terrain, it no longer gets to use Deflagrate, as we're no longer attacking at I4?

Super-heavies have Move Through Cover, so it's still at I4.

[DWest]

Super-heavies have Move Through Cover, so it's still at I4.

Incorrect. Under "Charging Through Difficult Terrain" in the Assault Phase section:
"if at least one model in the unit moved through difficult terrain as part of its charge move, all of the unit's models must attack at Initiative 1, regardless of other modifiers, even if the charging unit is not slowed by difficult terrain."

Neither the Move Through Cover rule nor the Super-Heavy Walker rules have any text saying they ignore this Initiative penalty.

[Gir]

Incorrect. Under "Charging Through Difficult Terrain" in the Assault Phase section:
"if at least one model in the unit moved through difficult terrain as part of its charge move, all of the unit's models must attack at Initiative 1, regardless of other modifiers, even if the charging unit is not slowed by difficult terrain."

Neither the Move Through Cover rule nor the Super-Heavy Walker rules have any text saying they ignore this Initiative penalty.

Okay.

It still doesn't change that Deflagrate only works with normal attacks, and Tempest Attack is explicitly stated as not being a normal attack. Not sure how you're having so much trouble with this.

[DWest]

Because that's how it works. There is no way you can take an order-of-operations indicator which is what the word "normal" means in the Deflagrate rules and stretch it to be some sort of restriction.

[Gir]

Because that's how it works. There is no way you can take an order-of-operations indicator which is what the word "normal" means in the Deflagrate rules and stretch it to be some sort of restriction.

You can, because the wording defines normal attacks as ones made using normal combat rules, and defines Tempest Attacks as not normal.

It doesn't matter that tempest attacks calls Deflagrate, because the first you do when deflagrate is invoked is check for normal attack, which Tempest fails, so you skip the rest of the text.

[DWest]

Your interpretation is still incorrect, because you're not using normal correctly. It is only there for order of operations: Attack > Wound > Save, then Deflagrate. That is the only thing "normal" refers to in the Deflagrate rules.

[The Emperor]

Your interpretation is still incorrect, because you're not using normal correctly. It is only there for order of operations: Attack > Wound > Save, then Deflagrate. That is the only thing "normal" refers to in the Deflagrate rules.

That's an incorrect interpretation of the rules. Deflagrate keys off of normal attacks. Tempest Attack specifically states that it's done in place of a normal attack. Therefore it doesn't meet the "after normal attacks" requirement necessary to activate Deflagrate. It's pretty simple.

[DWest]

No, you're still wrong. That is not how the wording of Deflagrate works, and repeating the wrong interpretation won't make it right no matter how many times you say it.