If you want a spell effect to last forever (unlimited bound weapons, untimed summons, etc.), you can create them. Create a spell that mixes the desired spell effect with a Soul Trap effect. Aim the spell straight down at the ground to get an unlimited spell effect. Note: You have to own a spell that has the desired effect before you can use that effect in enchanting or spell making. Magic effects that cancel themselves for any reason other than time will cancel for the same reason (for example, invisibility or a summoned creature dying). Do not use spell effects that you will want to cancel later (for example, unlimited water walking).