She can summon up to three Servants at once. These minions have a base duration of 8 seconds , which decreases by 3 seconds every time they are hit by Jack-O' or another servant.
Understanding Jack-O' requires mastering her unassuming but effective normal attacks, many of which serve as "abare" (moves to interrupt pressure). GGST - Jack-O Overview - Dustloop Wiki jacko dustloop