I have grievous @ 6* now (all abilities level 4 and 5) and I gotta say, I'm unimpressed. I have spent considerable TIME and EXPENSE to acquire him and I feel as though I've been had. Maybe at 7*, gear level 12, he's unstoppable, but it would be 2x the TIME and EXPENSE than b4. The point is that a character that is this difficult to get should be a superstar from the moment he's unlocked. I believe the devs should give him an immediate infusion of health and power, and then apologize to us, the diligently myopic grinders, for basically running a con.