Originally Posted by CSocktaters

Should I save a lot of pero for this event or is it not going to be used as much. I have a method when teasing others where I hold the mouse in one spot to click all the buttons and then move it to the far right and pick one of their friends, rinse and repeat. I used a lot of pero trying to get those limited cards from last event and have 36k~ left. Also I'm focusing my missions on the ones that gives money to buy gacha which I find is better than buying more N wilds from the store because you have a decent chance at getting SRs and Rs leveled up as well.

You won't need any pero for this event, outside of buying dozens of N-Gacha Tickets to speed up leveling up your cards.

JP event periods seem to suggest that Colisseum will run from next Monday (20th) to first Sunday of August (2nd), and then the next Guards event will be up around Monday 10th.
If it's so, then you have less than 30 days to rebuild the recommended 500k pero for Guards