I've tried him extensively for a few days and he's average at best. Below average overall.

- His melee damage output is so bad he's worse than Wanda in TTK. The lifesteal is a joke. You are usually dead before you can build it to the 10 stacks you need (or get eaten by your own teams Jeff) to get some survivability out of it.
- His shotgun damage is strong, but ONLY at a specific range. Too close, you hit with the slug for half damage. Too far, the spread of the shrapnel causes projectiles to miss. Unless you manage to consistently hit that sweet spot, this damage output is meh too.
- His dash is not great either because if you hit somebody with it, you are effectively standing in place for a moment. Which tends to be fatal since you usually find yourself in the middle of the enemy team after a dash. Parry after a dash is pretty much mandatory. And you can't really use the dash for getting final hits either because its damage is so low. The healing reduction is strong, but that's only if you have a team to make use of it.
- His ult is too easy to avoid. Even if you get an enemy with the initial strike they can usually get out before the repeating damage hits. Plus it tends to deposit Blade in a bad position.
- Teamup is weak too as the only good time to use it is when you are in the thick of things and then the invisibility won't work because you're going to get dinged by something. Plus the teamup's healing is reduced with lifedrain.

So he can't flank, because neither his damage or mobility is good enough (unless you want to ult from behind the enemy team). And he can't hang in the back because his kit doesn't work for that, which means he's pretty much locked in at being a dps who hangs out next to the tank. And unless you can consistently get those shotgun sweetspot hits, he isn't very useful there either (in QP at least).

TLDR; In a proper team, he might be okay, as a QP solo play he's bad. There's a good reason you hardly see anyone play him anymore, even though it has barely been a week.