Black Heart Archon and Sslyth bodyguard

Hi guys, I'd like to get some confirmation on the interaction of the Black Heart and Cold-blooded Bodyguard rules

Let's say I have an Archon and a Sslyth from a Black Heart detachment on the table, within 3" of each other.

The Archon lose a wound (because either I failed his Shadowfield save or because the original attack caused a mortal wound). Now I can take the 6+ FNP on him

If the FNP is failed too, I roll for the Cold-blooded Bodyguard rule and, if that roll is successful, the Archon is uninjured but the Sslyth now take a mortal wound. Now I can roll the 6+ FNP for the Sslyth (thanks to being Black Heart)

So, basically, I get two FNP rools against that original attack

Is this process correct?

Yeah, that seems about right.

Yup, looks like it.

Good!

Thank you, guys