One can say that this event has 3 stages:

1) Increased Chase damage -> you have to build your team around highest possible chase dmg (so ninjas like Kotetsu that have both scaling and super hard hitting chase are key on top of support ninjas like Genma / Ashura, Xmass Kushina or writer jirayia)

2) Increased Standard damage -> you have to build your team around highest possible standard dmg (select ninja that can drop multiple hard hitting standards or one that makes entire field with scaling clones that do the job for you like sai)

3) Increased Mystery damage -> you have to build your team around highest possible mystery dmg (Ninjas with scaling and hard hitting mystery with resets are priority like GNW temari etc)

and that's it.