How precicely does "gain an ability" work? Is that ability effectively added to the end of the character's ability? Can it be activated first?
For example, say I'm running Judges. I block with Lying Spirit while Moses is in play, So I get to choose a human hero in my territory to gain the ability "Choose a human king to block. Limit once." If I give it to Jephthah (J) in my territory, does his discard activate before the choose? Conversely, if I give it to Prisoner in Gaza, can he choose a king to block before swapping out for Jephthah (allowing Jephthah to target the king in battle with his discard)?