Maelstrom
Your Weapon Shots reduce the Cooldown of Shock Pulse by 0.5s and Shock Pulse bounces 4 more times.
Shock Pulse
Arc Lightning
The bounce range of Shock Pulse is increased by 12-60%
Shock Pulse
4
Lightning Rod
Hitting a champion with Shock Pulse heals for 30-150.
Shock Pulse
4
Thunderstruck
Recharge 6-30% of your ammo for every unique enemy hit by Shock Pulse.
Shock Pulse
1
Outreach
Increase the area of Healing Totem by 10-50%
Healing Totem
3
Shamanic Might
Increase your base maximum Health by 100-500.
Armor
3
Guide
To start, I have a 67% win rate with Grohk and 2.53 KDA. And I could thank this build for getting it up there slowly. To me, Grohk is a very poor Heal focused champion and his totem is unreliable. In order to focus Heal with Grohk, you take away a ton of his potential damage and don't get all that in return in heals for teammates. He should be prioritized Damage and supporting himself first. Luckily, this build is focused heavily around self sustain:
9 full jumps of Shock Pulse = 54% Recharge of Ammo and 1080 self heal. You can cast Shock Pulse every second when hitting an enemy (works on deployables and shields as well) and it takes a full 5 seconds to run out of ammo so technically, you should never run out. In theory, you can dish out about 2k dmg every 1.5 or so seconds non-stop. Thus why this build is amazing. There's almost no reason to not have the highest damage every game (and I'm not kidding).
Item focus: Morale Boost (I will explain below), Caut typically but may need Wrecker or Bulldozer to fit the situation, and Kill to Heal--Defense can be whatever the situation needs which usually is Haven for me.
Now why Morale Boost? Play a game with this build and spam shock pulse and you'll see why. I've had games where I can cast my ultimate twice per round comfortably. And also, with the buff to his ult, you are very mobile thus making you incredibly difficult to hit and also can cause the enemy to disperse. Your Ultimate can pump out 5k Heal and 2k dmg to single targets if struck with every hit over 5 seconds. Though it may not be as great as other ultimates, the fact you can spam it makes it an incredible pain in the butt for the enemy and can save your teammates who need help quickly. And I have tried Chronos many of times and just never got the same results. Like I mentioned earlier, Totem is not reliable enough to make Chronos a good pick unless with a team that has good coordination.
Your hopes in a game are to not be the healer but still have another true support like jenos or furia. Both pair very well with Grohk alongside a tank like Fernando. But if you do get stuck being the healer, it is not the end of the world. You'll just want to keep your head a little more on a swivel to try and help teammates out. The key with Totem is to place it in an area that is out of sight of the enemy such as behind walls. Don't worry, you can heal allies through objects. The same is said if you have to heal yourself. You also want to place it in a way where multiple teammates can utilize it. This is much easier said than done since a lot of teammates might be clueless to immediate surroundings. And always note that Pulse Shock heals you for a ton in a quick moment. So if you can use Totem to help an ally and then pulse shock to heal yourself, always do so.
This is why this build is so dangerous. Ridiculous group fighting potential (like I said, 2k dmg every 1.5 seconds); can still focus and burst down a single enemy with about 1.3k dmg per second roughly (as long as they are near other enemies including deployables--AND YES, pulse shock jumps to deployables so use this to your advantage!!!!); and has great self sustain while adequate healing potential for enemies with the ability to spam ult for great moments of major recovery for the team. What little bit you lose in Heals, you make up with massive amounts of dmg.