As long as Sarlacc is in the Ground arena, this Location can't be discarded.
When the battle phase starts, you may choose one: Put 1 captivity counter on a unit in the Ground or Character arena. Or: Put 1 damage counter on a unit with 1 or more more captivity counters on it in the Ground or Character arena.
Each unit gets Backfire 2 when attacking a Tatooine Creature