as In can a friend and I just fight against each other if we aren't interesting in the single player/pve stuff. As in just like fighting games?

It is really hard to find any information so I hope some of you can help me here. Is the Ultimate Edition a better deal content wise or is it better to buy base game then DLC separately?

I'm a japanese student that likes to use my time playing games to learn japanese at the same time, is there a way to change the langague of the game to japanese? When i'm in game i can select a lot of languages, but japanese is not appearing there, even chinese is for some reason, anybody knows how to add japanese?...

I bought two charter pass, what other content should I purchase

With the sale on going I was curious if the online coop is synced properly or is this reminiscent of other KOEI DW games where mobs are not synced at all from one player to another?