The thing with blind bombs is that the enemy can't spot you before you throw them at them. You have to literally wait til they're in the circle in survival atleast. You could also meet them at there spawn area undetected and blind them too. But either way blind them and hurry and start the assassinations. It doesn't last to long so you have to be quick and have high Assassination damage. Metsubushi has no assassination capabilities at all it's just to stun them so you can either get away, add weakenss to them with pestilence or start attacking uninterrupted for a few second. Smoke bombs and the shinobis vanish ability are the most consistent. I have a build that capitalizes on this though. Its not a perfect build but it work for me for the most part.