[3.5] Furious Evoker PrC [PEACH]

[Heliomance]

Energy Substitution (All) and Energy Admixture (All) really aren't the equivalent of ten feats, more like 4, especially when they're likely to know spells of suitable elements to begin with.

They really are the equivalent of ten feats. To whit:

Energy Substitution [Acid]
Energy Substitution [Cold]
Energy Substitution [Electricity]
Energy Substitution [Fire]
Energy Substitution [Sonic]

Energy Admixture [Acid]
Energy Admixture [Cold]
Energy Admixture [Electricity]
Energy Admixture [Fire]
Energy Admixture [Sonic]