Damage marked on permanents won't be removed until you actually get to the cleanup step (which will happen after your second end step), and "until end of turn" and "this turn" effects won't end until the cleanup step either
Introduced in the first Commander precons back in 2011, its been a mainstay in the format since its release
MTGO Commander 1v1 Banned List Update July 5th, 2017 Effective Date: July 5, 2017 (with the downtime) Next Announcement Date: August 28, 2017 [card]Vial Smasher the Fierce[/card] is banned [card]Ponder[/card] is banned
You'll start with your normal modern-day clothes, but as you progress through the game you will be given additional outfits and can purchase others too
If you want to see an Orvar deck in action, I highly recommend watching this episode of Extra Turns, where Josh Lee Kwai showcases some of the the cool stuff an Orvar deck can do