You collect 264 seals (so you can pull 300 times when the rebate comes) and wait for the event called Recruitment Feedback. Once the Event arrives and you got the required amount of pulls you pull 300 times (not a single pull extra). Once you get past 900 pulls into the tresaure i would consider pulling every time you get to 10. It may not be the most efficient way to pull but you'll get that super rare faster.