Complete the indicated task to unlock the achievement.

Achievement	How to unlock
A former ally	Kill one of your former friends.
Burn them down!	Kill 10 enemies with an explosive barrel.
Collection complete	All Blood Coins collected.
Let them fly	Kill 10 enemies by pushing them into a pit.
No deluge this time	Blood Seal returned.
No time to sleep!	Revive your co-op partner 10 times.
Ooops I did it again	Kill your co-op partner with an explosive barrel twice.
Real Vampire	3 vampiric decisions made.
Still Human	3 human decisions made.
Suck it	Suck 1000 litres of blood.
Team player	Play through any act with a co-op partner.
YOU SHALL NOT PASS!	Roya stayed unharmed collecting the vampire blood.