This card packs a lot of potential power - The downside is, it

demands a lot of life, and black mana. So, if playing mono-black, it

may be your go-to, but you'll want to use a fair bit of lifelink for

regaining the losses. Theoretically, it won't be difficult to manage

your life situation, as long as you can control the board. Taking a

half-life hit may seem like a stupid decision, but with a proper

setup, it is relatively insignificant. Just make sure that you can make

continuous gains, and the "1/2" is always just a factor. For

example, say you have your starting total. If you are posed with a

threat that will inevitably maintain an advantage over you, sacrificing

half your life to kill it might not be a bad idea. After the fact, you'll

still have 10 life (Significant enough to take a moderate blow), and

you might sneak in a Mark of the Vampire on a flier. Say it makes

you a 4/4 flier, and you have a clear path to make back some life -

You'll then have 14 life. The opponent might put something out to

block you. Sacrifice again, you have 7 life, you cleared the path, hit

to take it back to 11. So, on and so on, as long as things remain

stable, you could kill a 3rd creature, hit again, and end up with 10

life still. You see? The first sacrifice took you to 10, and you might

end up with that same total after 2 more kills, with a good setup.
Eighth Edition
8ED Black