Atar, the stone guardian

Reincarnation. Not really what youi meant by passive, but...

Yeah the hero idea is...A bit all over the place. Do you want him to tank? carry? support?

The ultimate, for what it gives, the cooldown is waaaaayy too high. It's not really game-changing except maybe to give that extra health to escape a bad engagement, but 180 cd...And the only time it's really any good is with aghs, but that's with a full carry build to make use of the bash you can get with a much cheaper item. Without aghs, it's literally just extra hp and a small slow on attack effect. Really not worth.

Hot DAMN I would max earthquake. Such a cool ability. Feels a little like a targeted Epicenter though.

Stone shield is...Strange, to me. I don't know why, it just feels out of place.

Resonating strike. Where did I here that name again? Oh yeah. League of legends, nvm. I'm sure you didn't intentionally copy it. However. Take this at level one, win every single fight early. Instant 300 damage and 1.5 second stun? Which spreads to enemies? I think maybe make the damage scale, that's a bit broken.

Other than that, this hero's moves feel like they take inspiration slightly from existing moves. Epicenter = Earthquake and Echo Slam = Resonating strike (sorta).

It's a pretty fine idea, needs some heavy tweaking on the numbers side though.

TL;DR: Ultimate isn't good. Even with aghs. Other moves need balancing slightly. Especially Q.