Look up the FTL setup. It lets you change which character you are controlling everyone else with.

Entoptic said it right. As soon as pally gets sapped drop your magma and earthbind as you change which computer/account you are controlling with. If he is already on you then thunderstorm and LB/CL/ES him. If he is 70 then start running and dropping your earthbinds as you go.

Most of the time after I thunderstorm them they don't come back for more when they see sap'ing the pally didn't make me an easy target. Sometimes they go get a few friends and when the griefing starts I just log my second team and level for awhile.