FlyingFlying is an evasion ability.
A creature with flying can’t be blocked except by creatures with flying and/or reach. A creature with flying can block a creature with or without flying. (See rule 509, “Declare Blockers Step,” and rule 702.17, “Reach.”)
Multiple instances of flying on the same creature are redundant. (CR 702.9)
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a +1/+1
counterTo counter a spell or ability is to cancel it: remove it from the stack without resolving it. A counter on an object or player is instead a marker that changes characteristics or interacts with rules or abilities; for example, a +1/+1 counter modifies a creature’s power and toughness. (CR 701.6; 122.1) on each tapped creature you control, then
untapTo untap a permanent, rotate it back to the upright position from a sideways position. Only tapped permanents can be untapped. (CR 701.26) them.
Choose a BackgroundThis ability allows a legendary creature to be your commander alongside a Background with the stated relationship. (CR 702.124) (You can have a Background as a second
commanderA designated card for a Commander deck, governed by the command-zone, color-identity, and Commander rules. (CR 903).)