id like to make at least 1 lightning on target spell that does decent damadge but can be cast about 15 - 25+ times before i need to use a potion or run away well my magicka regenerates (100 intelligence and 93 will-power have about 300 magicka total)

also should i make a spell that does 4 seconds of paralyze with 6 points of shock damadge for 15 seconds on target now or when i train my destruction to 100 and then train my illusion to 100 ? or whats the best paralyze + shock damadge over time on target spell i could make currently have 78 illusion and 82 destruction