Electrolytic serum/Legends

"The syringe on the platform contains a highly electrolytic serum that will allow you to pass through the shield. However, it is toxic to all but one of you."

- Moralo Eval to the tournament contestants

Electrolytic serum was a substance that when injected into the bloodstream of a particular species, allowed them to pass through an electrified ray shield.

History
"He's a Parwan. His blood can take the electrolytic serum."

- Obi-Wan Kenobi, to the other contestants

During the Clone Wars, the Jedi discovered a Separatist plot to kidnap Chancellor Palpatine during a celebration on his home planet of Naboo. Obi-Wan Kenobi, disguised as assassin Rako Hardeen, and joined forces with Cad Bane and Moralo Eval, the mastermind of the kidnapping plot. After arriving on Serenno, Bane and Hardeen were were invited by Count Dooku to join ten other bounty hunters named Sixtat, Embo, Twazzi, Mantu, Jakoli, Kiera Swan, Onca, Bulduga, Derrown, and Sinrich in a tournament of skill within The Box.

After two tests were completed, eight surviving competitors were enclosed in a room blocked by electrified ray shielded floor and three walls. The fourth wall contained a switch to deactivate the ray shields, hidden behind a small ray shield. A syringe containing a highly concentrated electrolytic serum toxic to all but one of the six remaining contestants stood in the middle of the room. The Parwan Derrown's physiology allowed him to survive the serum injection in order to pass through the shield relatively unharmed and deactivate the remaining shields.