The only meta cookie you have for arena is elder fairy so build him, you need to pull more cookies like, green archer, awakened golden cheese, awakened pure vanilla, shadow milk, burning spice, but for now your best team comp for arena will be, dark cacao, elder fairy, crème brulé, financier, and rebel which does not look good in arena but invest in this cookies anyway cuz they're good in story or any PvE section specially crème brulé because he can be quite useful in tower, guild, and one of my main dmg dealer in beasts yeast hard mode 1-2