What lolerster said - it doesn't replace Blood Contract, it complements it. You can click on it for *1.1 damage boost, then switch to Blood contract for another *1.1
Alternatively, you can stun the monster (or use celerity, blind, choke, terror, cold, etc) and stack like *1.5 damage boost in one turn, which is like equiping a second CIT.
And, of course, it works fairly nice for beastmasters, since they suffer somewhat fierce from a lack of guest-boosting miscs.
P.S. Also, and I can't believe I just noticed it, it scrambles monster resists! You can now change monster resists to fit your strongest nuke (WKZ, Frostval past weapons, etc) w/o a turn cost. Hell, you can even run with a single nuke set-up, scrambling monster resists to fit it!
< Message edited by Primate Murder -- 2/14/2020 1:13:13 >