[Shujin]

I agree that Eliminate sorta lacks the OMPH it's supposed to have, it looks really strong on paper, but it has already been explained how it just doesn't pan out as good.

I think certain defeat seems fine as an effect for it even if its a "Checkmate" thing. It just fits with the whole assassin business and doesn't take value from Blackbolts interference.

both approaches are fine, but I agree slightly more with Koonies. (100% hit basic attacks are iffy to me, personally. Its just auto attacks with extra. My personal approach would be bonus +hit/crit chance based on VE consumed)

I would like to suggest an animation style, I thought something similar to Firebird's spear throw would be swag. Like red screen, sprites turn black, and then some sort of Slash/blood splash animation, giving it a bit more ninja assassin style similar to assassinate moves in other games, which would be more in line with one big meaty strike.
Basically the "you are already dead" kind of animation.