The Nipissing (Nbisiing) are an Anishinaabeg
Indian First Nations tribe in Ontario:
https://en.wikipedia.org/wiki/Nipissing_First_Nation
Anishinaabemowin doesn't really have standard writing, uses a borrowed orthography, and has many different dialects and related languages so there tends to be some phonetic spelling, but the double-vowel system is pretty well established. Meaning "Nbiising" and "Nbisiing" are pronounced two different ways -- an 'i' indicates a short vowel like "bin" and 'ii' a long vowel sound like "been". It's also a very complicated language when it comes to grammar. As for the 'words' he's using...
Baabaa kind of means father, but it's not a complete word without a personal prefix. He might mean obaabaayan?
Diniim? Given the context he might mean 'nindiim' to mean "man" as 'nind' is the prefix for me and 'indininiiw' means "I am a man". But...that's not how it works.
Mishome is another incomplete word; 'mishoomis' is a dependent word stem meaning grandfather. It should be omishoomisan.
Sayenh is another incomplete word that I think he's trying to use to mean older brother, which should probably be osayenyan.
Gwiss is another word that is incomplete; ningwis means "my son", but you can't drop the personal prefix 'nin' to just get the word son; ogwisan is likely the correct word.
The language, especially when it involves relationships, depends a lot on prefixes and specific connections. The word you use for your mother's brother (cross-uncle) is different than your father's brother (parallel uncle). There are specific words for your own older brother and younger brother. Family is based on kinships and a clan system because it matters who your relations are.
So yeah. Dude's LARPing.
Nipissing First Nation Father. Man. Grandfather. Older Brother. Son. Gagiinawishki.