So i just log in and that is it for offline mode or ?!

[⚔ Kassandra ⚔]

?!

[VaLiuM]

I guess, once it loads all assets in the beginning, you should be able to keep playing.

"What content/modes will be available offline for MultiVersus after Season 5?
After Season 5, players will have an option to enjoy MultiVersus offline via the local gameplay mode, either solo against A.I. opponents or with up to three players, as well as the training mode (The Lab), with all characters unlocked and playable."

"Can players reinstall MultiVersus after Season 5 ends?
Players who delete/uninstall the game prior to the end of Season 5 will be able to reinstall after May 30. Please note, to access earned and purchased content offline after May 30, players will need to install/download the latest version of the game and log in during Season 5 (February 4 through May 30). After logging in, a local save file will be automatically created connected to a PlayStation™Network, Microsoft Store, Steam, or Epic Games Store account, to enjoy the game offline with all earned and purchased content moving forward."