Sanguine Bond

Sanguine Bond's ability triggers just once for each life-gaining event, whether it's 1 life from Soul Warden or 8 life from Tendrils of Corruption.

If you gain an amount of life "for each" of something, that life is gained as one event and Sanguine Bond's ability triggers only once.

If an ability triggers whenever an opponent loses life and causes you to gain life, such as the ability of Exquisite Blood, this will loop until either you win the game or a player takes an action to break the loop. If neither of these happen, the game ends in a draw.