This is my preferred All-Stars who have played only once! (Selections based on edit/audience perception)
Heroes:
Chelsea (One World)
RC (Philippines)
Lisa (Philippines)
Tasha (Cagayan)
Natalie (San Juan del Sur)
Jeremy (San Juan del Sur)
Spencer (Cagayan)
Yul (Cook Islands)
Ian (Palau)
Bob (Gabon)
Villains:
Ciera (Blood vs Water)
Kim (One World)
Abi-Maria (Philippines)
Kass (Cagayan)
Missy (San Juan del Sur)
Tony (Cagayan)
Ken (Gabon)
Marty (Nicaragua)
Vytas (Blood vs Water)
Shane (Panama)