Bumping this topic rather than starting a new one. Shinobi is a horrible replacement for Build-Up offering very poor damage potential, and Lotus Drops inexplicably has double the recharge of any other variant with no additional damage to compensate. Shinobi operates similarly to Targeting Drone, only it's much worse in just about every way (other than bundling in Stealth and a negligible amount of Defense), adding a mandatory 30 second timer between being able to receive the "opening attack" damage buff from Stealth and having a pitiful 6.25% damage bonus outside of the also laughable 50% on the one attack that you'll make, if timed absolutely PERFECTLY, once every 30 seconds.
Personally, to differentiate it from Targeting drone, I'd keep the low damage buff all the time (maybe buff it to 10% at least) and then MEGA increase the opening attack from Stealth component by a LOT. Like 100%, at minimum, to bring it more in line with Build Up, considering Build Up lasts for 10 full seconds (not 1 attack), and can be fired off every 45s with no effort and every 27s with Hasten. Personally, I'd opt for a 120-150% damage buff, considering it only applies to the one attack, but I also recognize that the power has other utility components as well, so it's not a sticking point. I'd also raise the DEF it provides by a bit % to give the power and set some added utility. Blinding Powder has some crappy mez secondary effects that last a few seconds, but its primary component, -ToHit, is a not so great 7%, and nothing else in the set provides ToHit debuff, like you'd think maybe Smoke Flash would. I appreciate the damage res debuff on Smoke Flash, it's one of the few redeeming qualities of the set, but a tiny bit of ToHit debuff added in would do wonders to help the set jive better together, because as of right now, it's a weird mixed bag of Def Debuffs from the katana powers, small amounts of Def to all and Res only to Psionic (a fairly rare damage type), a single decent resistance debuff, a single okay-ish ToHit debuff, and a rather bad Damage/ToHit/Def/Stealth buff. None of these things seem to really synergize well together.