
Wear your finest clothing when you go battle this month's Friendly challenger! I'm not sure it'll help, but hey. Dress for success?
The friendly challengers this year will not disappear after their month finishes.
Unfortunately, I don't think anything can really prepare you for this month's unfriendly challenger. You can unlock Diavester using the Pink Diamond Embedded Clay Figure from the Cash Shop. Good luck!

BUT WAIT, THERE'S MORE. The various Sylph challengers have stopped by to rain all over your day. You have until 11:59 on May 7 to battle Cloud Sylph, Dark Cloud Sylph, Lightning Sylph, Raging Storm Sylph, and Rain Sylph.
These challengers can be found in the Throwback tab of the Battle Coliseum.
All were very easy to beat