He was still in his elementary years when he thought of the possibilities of devising, combining, checking and balancing techniques and forms to come out with a distinct more versatile style not easily predictable by existing Masters.
From his observations of these Eskrima exhibitions, he modified moves with an emphasis on three striking levels: the eyes, lower arms (specifically elbows and hands), and knees.
His PC commander in Camp Ketley, Dansalan, Lanao del Sur (now Marawi City), needed a bodyguard who was skilful in Eskrima.
Caballero applied for the position, but another known Eskrima fighter from llocos Sur by the name of Juan Carolla also wanted the post.
In the first round, Carolla was hit in the head which made him collapse and unable to continue on with the fight, giving Caballero the victory.
Anoy, who was from the nearby town of Tangub, was a formidable challenger as he was known to be able to bend an iron bar around his waist using his bare hands.
Tanciong Lopez, a boxer and eskrimador from Cebu, went to Ozamis to avenge the defeat of his teacher but was unmatched by Caballero; he was not able to deliver any blows.
In his prime, Caballero was the Juego Todo (All Out, no holds barred) champion and beat several famous Eskrimadors and some lesser known challengers.