Energy + Energy Regeneration + Movement Speed = Reserving Flood
Whenever you cast a spell you gain 1 stack of 'Reserves'. When you have less than 20% Energy you regenerate (Movement Speed Value) Energy per second for each stack of 'Reserves'. While generating Energy each spell you cast will add (Energy Value * 0.2) shield on you for 10 seconds.
Movement Speed increases the Energy regeneration. Energy increases the shield amount.