The design idea is super cool but attaching the whole power of that design to 2 low HP summons ist just plain stupid. Please give that champ a mechanic like the Rockforger has. The minions need to respawn. And while you are fixing that please also fix the Extispicer and Stormreader. These two champs push psy and ele themes over the top by a great margin.
I believe Sok stated somewhere that Bloodlust whatever the other abilities similar are getting nerfed soon. As for Megalith, it's tricky to buff it without making it OP. I agree that it currently sucks once the summons are dead.
I don't know if "Soon" is the right word, especially since I plan to do it with the revamp of Vuln/Hunter/Foes, but yea, it's planned. As for the Lodestone, it is kind of the point that and interest of the unit that the parts are integral to it and it is why it is allowed to have the stats it has at the cost it does. It's overefficient when the units are alive, and not when they are dead.
I haven't played the Megalith yet, but can you just pull the summons back and leave them in a safe zone, or are they meant to be in the action? Are they even stronger x2 with 4 summons?
They have to be close to the megalith for him to get the buff. Buff is maxed at 2 stacks. Having 4 out though does make it easier to get the buff and gives you flexibility with their positioning.