Phrecia build for saving FPS

I am trying to play the Phrecia event with a friend who can play the game solo between 40 to 15 fps.

Me joining in on a servant of arakaali (pconc of bouncing) tanked her fps to around 4 during rituals, so i am trying to find a build that is really light on her system.

She is playing a RF paladin, so i thought there might be some success with ignite slam, for a single hard hitting spell/ attack, but i could only find one build.

i was hoping some of you could recommend builds that are not very effect-heavy.