Tatsulok is a Tagalog word for Triangle, it comes from the two Tagalog words, 
Tatlo which means three and and Sulok which means corners, 
Three corners (tat sulok) therefor a shape of a triangle.

Triangle is also commonly associated to Filipino martial arts as well as the Filipino culture.
to learn more click the link here: TRIANGLE





Background story…
His name is Tatsu, he practice Filipino Dumog, the art of Grappling,
he was born not knowing his parents, he is an orphant who lives by his master
who took him as his student as well as his foster child, he has this amulet
that shape of a circle with a triangle with a Ka symbol embbeded to it.
little that he know that the amulet his wearing is one of the
shards of the Magical Tatsulok stone, that was buried by Bathala
in high mountains, a stone used for sealing all magic that human possess.

now demons are looking for the shards and its up to who ever possess the amulet
to stop them.. 

—-
I always wanted to write a novel base on this, 
but I never had the motivation to write the whole thing hahahah xD

The Austronesian-speaking peoples are various populations in Southeast Asia and Oceania that speak languages of the Austronesian family. They include Taiwanese aborigines; the majority ethnic groups of East Timor, Indonesia, Malaysia, the Philippines, Brunei, Madagascar, Micronesia, and Polynesia, as well as the Polynesian peoples of New Zealand and Hawaii, and the non-Papuan people of Melanesia. They are also found in Singapore, the Pattani region of Thailand, and the Cham areas of Vietnam (remnants of the Champa kingdom which covered central and southern Vietnam), Cambodia, and Hainan, China. The territories populated by Austronesian-speaking peoples are known collectively as Austronesia.

OPM is stand for Original Pinoy Music, it refers to a song written by a Filipino with Tagalog lyrics, while other languages has their own respective genre, such as Bisrock (Bisaya Rock), BisRap etc. by the Visayan people, either way, OPM is the General Music in the Philippines, listened by every Filipino, lately OPM is loosing popularity by the dominating music today such as American music, Korean Pop and other popular genre, but there are Filipino artist who seeks to revive interest for OPM and assure the future of both the artist and Filipino music’s extensive genre. “No less than the future of OPM is at stake in this campaign. It would be such a loss to our cultural heritage if we do not fight the bandwagon trend and just allow original Pinoy music to die out. It’s also in the best interest of Filipino musicians, especially the young up-and-coming artists, for OPM to continuously thrive. Our future as musical artists, and purveyors of Philippine musical culture, depends on it,” as Myrus quoted

Here is a wonderful OPM song by Vernsrock – Dahil Ikaw,
Video made by Jandrew1489