Volcano Hellion has echo {X}, where X is your life total. When Volcano Hellion enters, it deals an amount of damage of your choice to you and target creature. The damage can't be prevented.
2007-02-01
As Volcano Hellion's "enters" ability resolves, you choose a number. Volcano Hellion deals that amount of damage to you and to the targeted creature. You may choose 0.
2007-02-01
Volcano Hellion's echo cost constantly changes; it's not locked in when it enters. The echo cost you pay is equal to your life total as the echo triggered ability resolves.