Who is supposed to use this skill?
Healers? The skill puts the altar at the caster's location. Most of the time you don't want the healer up around all the enemies where your tank is.
Tanks? The skill has a 1.5 second cast time. Do we want the tank to stand still taking damage without block up whilst casting this skill?
Damage Dealers? Maybe... I guess... if they're melee or up close damage and don't mind using an expensive cost skill with a cast time that doesn't seem to fit into their job description.
Can we consider a change that allows Blood Altar to be either cast at a target location (would make it worth considering for a healer) or to remove the cast time (would make it worth considering for a tank)?