When Bladecoil Serpent enters the battlefield, for each spent to cast it, draw a card. When Bladecoil Serpent enters the battlefield, for each spent to cast it, each opponent discards a card. When Bladecoil Serpent enters the battlefield, for each spent to cast it, it gets +1/+0 and gains trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.) and haste (This creature can attack, and as soon as it comes under your control.) until end of turn.