Equip your character with Quickboots (the ones you can buy in Vane for 80,000 silver). If you equip the character with two Quickboots, his skills should be two to four times stronger than before, in addition to increasing you NOA by four. You can easily do 999 damage this way. Note: this only works on Alex and Kyle, since they are the only ones that can do physical damage with their skills, It also works with Jessica's Crimson (her second special attack).