Sixty-one-year-old Ricardo Sebastian looks like a nice, grandfatherly kind of guy. But don't be fooled - he is no man to mess with.

Pit him against any challenger, and the soft-spoken guy springs into action. Tom Aylor, who ran a karate studio in Grants-ville, discovered this a couple of years ago when the 5-foot-6-inch, 150-pound Sebastian walked into a karate studio and asked Aylor if he wanted to "try him."Aylor said he hesitated to take a stick against Sebastian, who reminded him of his father, but Sebastian insisted.

"I went to hit him with a stick, and he did a maneuver and blocked it . . . and then the stick was gone . . . and then he had it," said Aylor. "You'd never think that some old dude off the street could do that."

Sebastian proudly tells stories of astounding other martial arts experts, many of them younger or larger than him.

"Master Sebastian's system is deadly," said Gary Ruby, executive director of the U.S. Kali Association, an organization that honors Filipino self-defense experts at an annual awards ceremony in El Paso.

So powerful are the tactics of Filipino martial arts, they are used by U.S. Navy Seals and Marine Corps Reconnaissance to train, said Ruby. These martial arts systems have been in place for about 2,000 years.

"Grandfather" Sebastian was recently inducted into the Filipino Martial Arts Hall of Fame at this year's ceremony in El Paso, one of 36 honorees.

Sebastian, the world's only master of kamagong, became the art's top warrior in 1957, when Master Francisco Andukal passed the title to him on his home island of Luzon.

One of 115 self-defense systems practiced in the Philippines, kamagong uses weapons and direct moves to defeat opponents.

In January, Sebastian demonstrated some of his kamagong techniques to a SWAT team from the Utah Highway Patrol Police Academy, showing them how to take out an armed terrorist without dropping their weapons.

The funny thing is that Sebastian isn't very loud about his knowledge. All he wants to do, he says, is teach people how to protect themselves. And how to make peace.

Last year, he published a book called "The Turtle," which covers some of kamagong's basic self-defense moves using punches, kicks and weapons. The first of two volumes, the book's title comes from Sebastian's spiritual name, given to him by his kamagong master, who died 25 years ago.

Like the turtle, Sebastian believes that it is not necessary to kill an enemy to defend yourself, said his assistant, Scotty Gerton.

"I make advice," said Sebastian, his English revealing his Philippine roots. "We need to be calm, patient. No need to make mad to anybody."

For Turtle, who presents a seemingly gentle outer shell, it is the inner strength that counts most.