- last post: 01.01.0001 12:00 AM PDT
Halo's a separate series- Bungie will always be like this. And that Battle of Marathon- not specifically a space battle, but it could also be talking about some other time period, just for practice. Marathon, the ship, was never a battle, so it's not what is being referred to.
As is mentioned, Halo has many carryovers from Marathon series- the "Mark V" comment, the symbols, the races... (Hunters=Hulks from Marathon) and the AI's have connections: Cortana is one of the blades that is sister to Durandal. Both are rampant, both have run into powerful alien computer systems and structures.