How an asynchronous challenge feels
An asynchronous battle separates the challenge from a real-time match. You can issue a challenge and return later to its result rather than waiting in a lobby for another player. This is different from the game's offline PvE loop: PvP participation still needs a network connection.
Friends and leaderboards
Direct challenges are available for Steam friends. The game also includes global and friends leaderboards, giving you two ways to compare progress. Both leaderboards are online features.
Four PvP bosses
The four PvP bosses offer gear that is unavailable from other sources. The public game description does not provide a full boss-by-boss drop table, so this page does not attach specific items to individual bosses.