Slake the Thirst after action resolution

Perfectionist
Archetype.
Put this card on a vampire you control. Once each turn, this vampire can gain 1 blood after performing a successful action during which no reaction cards are played. A vampire can have only one archetype.

Slake the Thirst
Sanguinus
Only usable after this Blood Brother gains blood.
san COMBAT Choose another ready Blood Brother of the same circle. The chosen Blood Brother gains the same amount of blood.
SAN ACTIONMODIFIER As above, but usable as an action modifier.

Can Slake the Thirst be played when gaining blood from Perfectionist?

Snodig wrote:

Can Slake the Thirst be played when gaining blood from Perfectionist?

Per the ruling [LSJ 20100325] yes you can.

LSJ wrote:

> In [LSJ 20091120] (I cannot provide the link - title of thread "Predator's
> communion after combat? ") it was stated that explicit card text is needed
> for an action modifier to be played during/after resolution.
>
> Does the "Only usable when this vampire gains blood" text allow it to be
> playable after resolution of an action ? In other words, does that "trigger
> condition" override
It specifies when it can be played, so yes.