I need ideas.

The Outcast had gotten master chief's armor from a shady store. The Outcast didn't know what legacy this armor held though

He often spends time at air soft arenas.

I like that idea. Canon

Since he's an Outcast, he lives on a remote jungle planet where he fights alien wildlife

I'll think about it

I was about to roast you for having master chief as your oc but then I read the comment

Anyway the headcanon I have is that he’s fatherless, get it? Because he’s the “outcast”

Read this please
imgflip.com/i/7ozsne

he immediately shoots any stupid 10 year old who confuses him for Doomguy or Samus. /j

Maybe

He was welcome among the Eggs, and had many friends and allies among them.

Yes

Maybe even a wife (idk about that one)

It definitely cannot be an Inkla as a wife since the Outcast... was outcasted/ exiled from the inkla family

You can't take away a family name unless he was adopted in which case his last name would be changed.

But they technically aren't Inkla anymore if they were exiled

Confoosin

But that's besides da point