Two portals, ten second cooldown. Portal is the strangest Electric spell and possibly the most versatile. Spell projectiles that pass through a portal get duplicated, which means positioning your portals correctly turns one well-aimed cast into two. Players can also use them to teleport.
Strategy
Place one portal near a Fireball or Strikes trajectory to duplicate the projectile mid-flight. The ten-second cooldown, the shortest in the Electric school, means you can keep portals up almost constantly once you have the rhythm. In co-op, shared portals let teammates double their spell output through the same placement.
Strengths
Duplicates spell projectiles passing through for double casts
Ten second cooldown, the shortest in the Electric school
Player teleportation adds repositioning value
Weaknesses
Value depends entirely on correct placement relative to other spells
Requires coordination with teammates to use optimally in co-op