Hark in MkIII for the first time

But Hark is casting the spell during his own activation so does his own extra handcannon shot benefit is my question?

Yes, it does. It's all ranged attacks made in the activation.

As for general Hark tips;

- Don't go full spam

Whilst our jacks hit really hard, they still have trouble one-rounding an enemy heavy without help. Hark offers nothing in that regard, so you need to have an actual force softening things up for you. It also gives you a better chance in scenario play, as you can have better units and solos. You can pretty easily get 6 jacks and still have room for a decent amount of bells and whistles.

- You don't always need Mobility

SPD6 is great, but even without it you can trample + reposition 10" to get up the board. If you need it, then you need it, but it is half his focus.

- Maybe not Jaws?

Jaws will get you more free models and Behemoth, but I actually ran Hark in AC last time I played him so I could get all the tankers and more useful mechanics. I've played him in WGK too, where the lane-clearing, advanced moves and warcaster safety outweighed the lack of Forge Seers.

- Marauders!

For a focus-strapped caster with a piece-trading game, the ability to absolutely belt something for just the power up focus is great, and it's your cheapest jack to start trades with. When it gets truly fun is smacking something far enough away that when you reposition, they can't just jump up and walk to you. If they have to spend one to shake, one to charge, there is almost no way they're getting the job done.

- Reposition

Given that all Hark will do all game is cast mobility a couple of times, feat, and hand out focus, it can be easy to forget that he actually does anything. Do not forget reposition, like I do... Every. Single. Time.

Your thoughts with Maurauders might have me playing the man again ;-)

I played him a bunch at the start of MK3.  But I think that was pre forge seers.  Getting him back on the table again could be a ton of fun - and the Kodiak Cloud Wall really _IS_ a thing - perhaps even more with Forge seers and Mauraders ;-)

Is he, though? On Feat turn you can have him sat at 16/21 no KD if he has a guardian Rager or something. That's pretty monstrous.

It's surprising how easily some boosted sprays will drop him and he's probably not camping much if anything. That stat line is also assuming they have no way to move him or the 'jack(s) out of touch.

Sure, if you have a shield guard and your opponent can't move him out of touch with the 'jacks and they don't have good boostable sprays... He is probably safe on the feat turn. That's a lot of 'if's though! He certainly still dies to things like Nemo feat e-leaps and Denny1 feated sprays.

He suffers from having pretty much no focus to camp and a low model count. TK casters or lists that can move stuff around (like Ret) can easily open him up for assassination.

Well, just had my first MkIII Hark game. It was actually my opponents first game in MkIII, so needless to say he was a bit rusty. I won when Beast 09 reached his caster, but this was only after he got Hark down to just three or four boxes (and he would have won with slightly hotter dice). Harkevich didn't do anything in that game that other casters couldn't have done as well or better, but I was using my Strak list with Hark subbed in and no other changes, so it wasn't exactly built to his strengths.

I have to admit it was relaxing in a way, not having to actually think about how to use my caster because there isn't really anything for him to do other than cast his one little spell. I'll play a few more games with him anyway; then I'll probably either go back to a Sorscha or, if I've finished assembling my conversion by then, Karchev.