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 enters,
tapTo tap a permanent, turn it sideways from an upright position. Only untapped permanents can be tapped. (CR 701.26) target creature an opponent controls.
DeliriumAn ability word has no rules meaning of its own. It groups abilities with similar themes; the text following it explains this card’s effect. (CR 207.2c) — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard,
tapTo tap a permanent, turn it sideways from an upright position. Only untapped permanents can be tapped. (CR 701.26) target creature that player controls.