Originally Posted by BliztForever
He probably meant both, get as many friendship point as well as farming stages.
If you're looking for Siren, but don't have Castle of Satan unlocked yet, you can farm her from Mermaid Feast in Neptune Glacier or Voice of Siren in Sea Cave Mercury.
The drop rate feels about the same (btw drop is determined the moment you entered stage), so depending on your stamina or which one you found easier to fight, just go for the one you're comfortable. (you can always only get 1 egg in one floor at most, so fighting 3 Siren won't really make a difference)
thanks a bunch, just have to grind out those guys you both mentioned for the dark team i sorta half have. again thanks a ton for all the input