Hmmm... Jikimya is a little too naive.
During the explanation, I could entirely see Azuma's train of thought, the idea is pretty simple... he just wants to boggle the minds of the Oumi faction with unnecessary slog.
As he is the first to make a move, he has a certain advantage, and as the Oumi faction doesn't have a galvanized leadership it would affect morale and buy time.
Jikimya really refused his best practical option, an early offensive... that yatagarasu condition clearly shows how things will go for him.
Not that Kozumi cares, he is just buying time for his own designs.
Since it seems kozumi come from the present, I need people to throw me theories about what he is and what the future of the story will be
Who he is could shine more light on his mystery, but what is simpler.
The special "glue" that he must have used to achieve his status as sennin, must be what allowed him the capability to time travel, not the mechanism for travel but the ability to endure the travel.
Whatever it is, it allows him to temporarily unmake himself... probably a defense mechanism that allows him to remake and stay alive, however this "unmaking" has an effect on his mind which is why he has an "external storage" of information.
What will happen in the future... well i can think a few possibilities, our crew discovers if he is a future Ozuno or not, they defeat or convince him to stop (this last one I think highly improbably on account of his mental state), they find a way or not to eliminate the bugs.
It is a lot of little possibilities that can fit or not together depending on how the author wants to go.
By what is implied, this story is already an alternated timeline different from ours but it somehow is still directly connected to our "timeline", so a lot of things can happen depending on the players already present or those that may appear.