You get 6 spheres for discovery, and a varying amount depending only on the LEVEL of the Boss for fighting him.

Does not matter how much damage you deal to the Boss, 200 or 200.000 damage, you get the same amount of nectar at the end.

I have a special team of 1 knight that at most do 600 damage for my allies to enjoy the rest of the nectar piñata, aka boss

(by the way, i have room for 2 more )

[MachThreeSlug beat me for like 3 minutes in that reply >.< ]