Reroll wound of 1 is great, the problem is that when this is your sub-faction bonus.
A deniable spell, that you can not even cast-off, and that is going to apply to only a few units that are actually shooting on the targetted ennemy... wow
Compare to Bkack Heart sub faction bonus:
- all units reroll 1 hit roll (shooting and CC)
- +1 level in power from pain table
Drukhari Cabals aren't comparable to TS cults at all. The only comparison for the Cults are the GK Brotherhoods and the Death Guard Plague Companies. For DG the Black Heart bonus compares to Inexorable Advance, then Plague Companies are on top of that and have no comparison with Drukhari stuff.
TS are a Chaos Marine subfaction already.