Flying (This creature can't be blocked except by creatures with flying or reach.),
trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever an opponent casts a spell, that player creates a
Blood token
(A Blood token is an artifact with ", , Discard a card, Sacrifice this artifact: Draw a card.").
Whenever Bloodvial Purveyor attacks, it gets +1/+0 until end of turn for each
Blood token
(A Blood token is an artifact with ", , Discard a card, Sacrifice this artifact: Draw a card.") defending player controls.