Episodes like this are 1 in 10000 and this screams Emmy nomination. There are episodes in drama series that work so well and provide such a payoff that it makes a series transcend from excellent to one of the greatest shows of all time.
Two recent(ish) examples of this are Ozymandias from Breaking Bad, and Chicanery from Better Call Saul. Both of these episodes took place after years of build up and provided a payoff that has made these two shows stand out among scores of others.
With Herogasm, The Boys joins the elite drama series echelon and I cannot believe how masterfully crafted this episode is. We have so many plot lines, that have been building over the past three seasons, finally mature and give us the best possible outcomes imaginable.
Frenchie and Kimoko come to the realization that they are killers with or without powers and that their attempt at a moral high ground in going after bad super heroes is not enough to cover the darkness that has enveloped them both.
Mother's Milk ties his severe OCD to the death of his grandfather at the hands of Soldier Boy and that his quest for revenge against bad super heroes has come at the expense of all those who love him, specifically his daughter.
A-Train has one of the most intense face-turns I've ever seen in drama. He realizes at Vought tower that he is a murderer and has no right to claim a high ground. He apologizes to Hughie, a real apology where he realizes that his need to be in The 7 by using performance enhancing V led to the destruction of so many lives with his brother now crippled due to A-Train's inability to rise above. With this knowledge, and realizing he will likely die doing so, he murders Blue Hawk at the (possible) cost of his own life as Blue Hawk would never have been brought to justice.
Starlight finally stops letting others control her and realizes there is nothing left to lose and she can no longer play the role of "America's Sweetheart".
Hughie completes his transition into a man who also will not let others control him, even though this will cost him everything. His vengeance against Homelander has now become his reason for living. While we have not seen any appearances of Robin haunting Hughie in seasons 2 or 3, Hughie now has revenge as his sole purpose for being. Hughie tried to do things "the right way" by partnering with Victoria for a year, only to find out he was being played the entire time. Hughie has had enough and was willing to die with Butcher during Soldier Boy's explosion if it meant the death of Homelander.
Butcher's "Scorched Earth" line mirrors Hughie's transformation. Butcher has accepted his team leaving him and has gone against the dying wishes of Becca to help raise Ryan so that he could kill Homelander. Nothing else at this point means anything to Butcher and he was also ready to die from Solder Boy's explosion if it meant the end of Homelander.
Homelander finally realizes his place as the clown. He was created as a puppet to promote Vought and those who loved him only do so out of fear or to use him for some reason. Stormfront only wanted him to begin a new era of facism and she killed herself when she realized he would not do this. Black Noir has abandoned Homelander and was the only other person Homelander could consider a friend. Ryan hates Homelander as a father. Starlight won't be further manipulated. Maeve despises Homelander and continued to go against him even if it meant being black-bagged and possibly killed. Even The Deep, his most precious stooge, only follows Homelander due to outside influence and only because being in Homelander's good graces could possibly erase the awful history of The Deep. Homelander is nearly killed by Soldier Boy, Hughie, and Butcher, and Homelander realizes he is the poor-man's Soldier Boy. All of the awful things that Homelander has done are for nothing as he is now alone and now aware of how fragile he is.
10/10 - This episode alone has made The Boys one of the greatest drama shows of all time.