ShiKage's Big Bang Paladin Build

Dual Charge formula:
primary % * primary advantage + (lightning % - 1) * 0.5 * lightning advantage
Lightning is never the primary charge if another charge is cast at the same time.

So say for example you have maxed Fire + maxed Lightning Charge, against a lit weak target
1.3 * 1.0 + (1.25 - 1) * 0.5 * 1.5 = 1.4875
148.75%
Or just lightning alone
1.25 * 1.5 = 1.875
187.5%

Casting Lightning alone is better.