From The TimeSplitters Wiki

Sergio
Unlocked by	Challenge > Behead the Undead > Sergio's Last Stand with Silver or Better
Species	Human
Size	Normal
Accuracy	5
Agility	3
Stamina	9
Fire Proof	n/a
Shock Proof	n/a
Default AI	4 stars
Native TimeZone	1924
First Appearance	TS2 Arcade Mode
Relations	N/A
Games	TS2

TS1 Gesture	N/A	TSFP Gesture	N/A
TS2 Gallery	The circus strongman, Sergio's incredible strength is tempered with a compassionate personality and love of life. He likes to tend his herb garden and collect first editions.	TSFP Gallery	N/A

Sergio is one of the performers that works in the Circus. He wears rather revealing clothing. According to a Challenge Mode synopsis, one of his acts involves shooting Crispin.

Challenges

Sergio stars in Sergio's Last Stand and Rocket Man in TimeSplitters 2.