Creation Kit - Basic Custom Spell

From CreationKit.com:

"Specifically, the magnitude at some taper time (time since the duration expired) is
magnitude = effect magnitude * Taper Weight * (1 - taper time / Taper Duration)^(Taper Curve)
For damage spells, the total damage done during the taper duration is approximately
magnitude = effect magnitude * Taper Weight * Taper Duration / (Taper Curve + 1)"