I’m fairly certain I understand the interaction between LeHuse and FCS but I want to make sure I’m interpreting it correctly.

If LeHuse has FCS and attacks an enemy that a friendly ship has locked, but he doesn’t, then he can’t use FCS as FCS says “if you have a lock”.

conversely if a friendly ship with FCS uses the FCS reroll, LeHuse can still use his ability and spend the lock because FCS says the locking ship can’t spend the lock.

Are these the correct interpretations?

7 minutes ago, Asaverino1019 said:

I’m fairly certain I understand the interaction between LeHuse and FCS but I want to make sure I’m interpreting it correctly.

If LeHuse has FCS and attacks an enemy that a friendly ship has locked, but he doesn’t, then he can’t use FCS as FCS says “if you have a lock”.

conversely if a friendly ship with FCS uses the FCS reroll, LeHuse can still use his ability and spend the lock because FCS says the locking ship can’t spend the lock.

Are these the correct interpretations?

I'd say that's correct.

LeHuse with FCS doesn't get to reroll using someone else's lock.

With FCS, it's even a bit more loose than your example. FCS is only a limitation on that specific attack. Since LeHuse is a separate attack from the original one, and so can spend it to reroll any number of dice. However, if any ship with FCS performs another attack, they can spend the lock on their second attack. Quickdraw can use FCS to reroll a single on the first attack, and when later losing a shield, can spend the lock to reroll any number of dice.

I agree with bitterfig's answer, just adding the image for reference since I don't think I've read this card before!