Yeah my dopamine hit is when I create infinite combos like casting spells to untap things to cast spells/proliferate/etc on like turn 3.
Yeah, putting the square block in the square hole. Infinite combos aren't complicated and don't require thought. It's not like trying to chain together a storm combo in vintage cube, where you have no control over how many pieces the deck will have and no guarantee you'll be able to get the count high enough to win - infinites in EDH are deterministic and usually involve 2 to at most 3 cards, with a zillion possible ways to tutor into the pieces. So you sit there, ignore the game, ignore the players, play solitaire, and then out of nowhere win.
Which wouldn't matter if not for how fucking insufferable combo players are. Look, I don't care if you play an infinite... if I can play things that shit on infinites. But god help you if you put an Ethersworn Canonist into your deck, because that's "unfun!" Tossed a damping sphere in to punish mana doublers alongside infinites? "Unfun!" So much as run 2cmc Lavinia and you'd better have brought some towels to mop up the crocodile tears, because why in the world should a combo player have even a single piece of interaction? Attack them first as an aggro player because you know, at any point, they can abruptly render the rest of the game pointless? They're gonna start shitting themselves like they're a cornered animal.
Eh? There are several colorless cards that completely dunk on mill as a strategy and it doesn't tend to have any way to deal with them, alongside plenty of colored cards that do the same (Gaea's Blessing). Constructed mill gets around this by running Leyline of the Void-style effects if an opponent has that board plan, but most of the commander payoffs for mill depend on cards actually going to the graveyard.
Mill's one of the more milquetoast strategies out there, with the exception of mono-blue Bruvac. You kill that player as quickly as possible, then board in the mill-hosers, because that deck is tedious to play against.
There are no legendary creatures who do something with energy except the two new ones.
Lae'Zel does increase the energy counters you get by one per instance, but she doesn't have any Backgrounds that pair particularly well with that effect.