Chikyu, Disciple of Udmoth

{2}{b}{b/r}{r}: Prevent all damage dealt to and by Chikyu, Disciple of Udmoth.
{x}{r}{r}: Deal X damage to target coloured creature, you take X damage.
{2}{b}{b}: Sacrifice any number of Colourless creatures, your opponents sacrifice X creatures
where X is the amount of creatures you sacrificed.