primadonna pure AP, evolution scales purely on base AP (ignores equipment AP).
gambler pure HV, metamorphosis scales purely on base HV (ignores equipment HV).
to point out, metamorphosis and evolution scales only on base stats, they ignore equipment stats.
metamorphosis scales positively with HV and DP (increases the stats), while it scales negatively with AP and LK (decreases the stats).
evolution on the other hand scales positively with AP (increases the stats), while it scales negatively with LK, HV and DP (decreases the stats).
which means, its a waste of stats to put AP on metamorphosis builds, or to put HV on evolution builds.
since both transformation skills only works with base stats, its simpler and much more effective to concentrate on one primary stats instead.
then compounding for the other needed stats, e.g. pure AP stat evolution build with pure HV compounds.
there are other builds that are far flexible, but those two basic builds are standard builds.
other builds like pure HP duke, pure HV duke, pure DP duke, etc. works well in certain aspects.
on one aspect, duke is much better than diva, since metamorphosis multiplies the base HV and DP stat by 3.5times!
where as diva builds ignores evolution entirely, HP, HV and DP works somewhat.
from experience, the most stable and consistent build i've gone with is pure AP primadonna with full HV/HP comps, zero AP comps.
the effects are profound as the base AP can supply the much needed AP, while HV comps are more efficient than HV stats.
on the other hand, the most useless build i've tried is a 1144 DP build duke, it was hilarious as nothing could damage me, but i barely do damage as well.