my last name: SISON (you might think of JoMa Sison the communist leader but no i'm not related to him)

BUT BUT IN THE PHILIPPINES EVERYBODY IS RELATED ( Sorry, couldn't refrain from that, that's an impression i frequently have...

I think Sison has a Chinese background to it. Usually family names ending with -son has a Chinese background (Tuason, Siason, Lacson).

How would you know if it's Visayan, Tagalog, Kapampangan or Ilokano?

I think names like Sison, Lacson, Locsin, Jocson, Dizon, Hizon, etc... are Chinese names.

I think Lontoc, Bagatsing are Indianized names.

Every Filipino I had met here and there or someone I know of has either Filipino or Spanish last name (family name). Sometimes I would ask myself what if our last names weren't changed? What would then be the most common last name among Filipinos? Would there be a much greater pride since we have our own identity?
Filipino last names are very distinctive, it is easy to tell whether an individual is Filipino. One experiment I made not too long ago was to look for Filipinos on a school yearbook from other schools (not my school) by only looking at the last name and not the picture. It wasn't surprising that I spotted all of them. The ones with non-Filipino last names were left out until I looked at their picture and they looked Filipino. I am aware of the similarities in looks between ethnicities so I took that into consideration.

Both of my middle/last name are Filipino. middle name is Filipino. last name is Chinese.
my middle name: LAYA (yes i am related to Juan C. Laya (novelist) and Jaime C. Laya (governor of Central Bank of the Philippines 1981-1984))
my last name: SISON (you might think of JoMa Sison the communist leader but no i'm not related to him)

My great great grandfather [on my mother's side] was Spanish with the last name of Atmosfera. But that name ceased to exist in my generation cause it's a female [my grandmother] who is directly linked to that name. Only my uncles carry it as their middle name and my mom and my aunt as their maiden name (before marriage).

BUT BUT IN THE PHILIPPINES EVERYBODY IS RELATED ( Sorry, couldn't refrain from that, that's an impression i frequently have...

Spanish, starting with an E up from Ilocos and Nueva Ecija. And Spanish with M, from the Visayas... Probably from the Claveria Edict. Or my Chinese Mestizo ancestors made it up themselves. Before that, there's evidence of Ilocano Surnames.

Mine is Korean

Mine's Filipino, specifically Visayan

The descendants of those who migrated to Mindanao from region 1 (Ilocos Region) about a hundred years ago who now know nothing about Ilocanos or the Ilocano language could still trace their roots because of their Ilocano last names.

Some of them starts with AG....... like Agpalsa, Agatep, Agcaoili, Agdeppa, Agbayani, etc.
Some with MANG.........like Mangaoil, Mangaoang, Manglapus, Manglicmot, Mangrobang, etc.
Some with successive same consonants....Like Battad, Caccam, Purugganan, etc.
Some with AOA at the end of the last name like Rumbaoa, Agpaoa, Litaoa, etc.

At least these last names can say something about their history and pinpoint their great-great-great grandparents' origin in the Philippines, maybe up to the level of a town.

The descendants of those who migrated to Mindanao from region 1 (Ilocos Region) about a hundred years ago who now know nothing about Ilocanos or the Ilocano language could still trace their roots because of their Ilocano last names.

Some of them starts with AG....... like Agpalsa, Agatep, Agcaoili, Agdeppa, Agbayani, etc.
Some with MANG.........like Mangaoil, Mangaoang, Manglapus, Manglicmot, Mangrobang, etc.
Some with successive same consonants....Like Battad, Caccam, Purugganan, etc.
Some with AOA at the end of the last name like Rumbaoa, Agpaoa, Litaoa, etc.

At least these last names can say something about their history and pinpoint their great-great-great grandparents' origin in the Philippines, maybe up to the level of a town.