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)
: This creature gets +1/+0 until end of turn. If this ability has been activated four or more times this turn,
sacrificeTo sacrifice a permanent, its controller moves it from the battlefield directly to its owner’s graveyard. A player can’t sacrifice something that isn’t a permanent, or something that’s a permanent they don’t control. Sacrificing a permanent doesn’t destroy it, so regeneration or other effects that replace destruction can’t affect this action. (CR 701.21) this creature at the beginning of the next end step.