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)
ScavengeScavenge is an activated ability that functions only while the card with scavenge is in a graveyard. “Scavenge [cost]” means “[Cost], Exile this card from your graveyard: Put a number of +1/+1 counters equal to the power of the card you exiled on target creature. Activate only as a sorcery.” (CR 702.97) the Dead — When this creature enters,
exileTo exile an object, move it to the exile zone from wherever it is. See rule 406, “Exile.” (CR 701.13) target player's graveyard. 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 this creature for each creature card exiled this way.