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)
When this creature
diesIs put into a graveyard from the battlefield. (CR 700.4),
clashTo clash, a player reveals the top card of their library. That player may then put that card on the bottom of their library.
“Clash with an opponent” means “Choose an opponent. You and that opponent each clash.”
Each clashing player reveals the top card of their library at the same time. Then those players decide in APNAP order (see rule 101.4) where to put those cards, then those cards move at the same time.
A player wins a clash if that player revealed a card with a higher mana value than all other cards revealed in that clash. (CR 701.30) with an opponent. If you win, return this card to its owner's hand. (Each clashing player reveals the top card of their library, then puts that card on their choice of the top or bottom. A player wins if their card had a greater mana value.)