Blood God Diciple' s Blood Feast and Swallow Whole? BGD and evolutions that can be taken multiple times

[deuxhero]

1:Can BGD use BF on a creature killed/KOed by the damage of swallow whole? Does it take any actions?

2: Can Blood Feast be used to manifest an evolution that can be taken multiple times in a separate way (such as Minor Magic)? This is particularly important for Synthesist, who get no mileage out of the (legal) combo if you can't.