
FlyingFlyingCan only be blocked by creatures with flying or reach., trampletrampleExcess combat damage it deals to a blocker carries over to the player or planeswalker it's attacking., protectionprotectionCan't be damaged, enchanted, equipped, blocked or targeted by anything with the stated quality. from Angels and from Archons
Players can't gain life.
When Balefang enters, target opponent creates a tapped Baneslayer Angel token. The token is goaded for the rest of the game. (It's a 5/5 Angel creature with flying, first strike, lifelink, and protection from Demons and from Dragons.)
Hover an underlined rule to see what it means.
Read from the rules text. A card that enables a keyword makes or is the thing; a card that rewards it gets better when you have it. Two cards interact when one enables what the other rewards.