First of all, Kimiko’s enriched uranium. We know uranium is a counter to compound v. When Homelander is trapped in the uranium room, he’s a lot weaker. He’s not that weak in the final fight, but clearly he’s slower and arguably less powerful. The presence of the uranium this time seems to be enough to weaken him but instead of directly hurting him it just lowers his power levels. The reason he seemed worse for wear in the uranium room is because it was a closed contained room and the uranium was directly exposed to him. 

A problem with the logic of kimiko’s uranium having a sort of passive poisoning effect is that it would also make her teammates ill. We saw this in the penultimate last episode. First of all, Hughie did imply it was bad for them anyway. Second, the uranium in Kimiko was more worked on/experimented on than the uranium Homelander got exposed to in the science rooms. Sage and Frenchie, with the help of 2020s tech, made Kimiko able to carry the uranium and seemingly have a passive effect of weakening compound v without the blast being used. I guess by this logic, butcher and starlight also should have been weakened. Well, Starlight always seems weaker than she should be so there’s that. Butcher’s powers are a manifestation of a tumor so maybe that gives him some kind of resistance/immunity against a substance that would essentially cause a tumor. 

Another problem would be the fact that Kimiko tanked Homelander’s lasers yet bled to bullets and got cut in half by his lasers earlier in the season. Well, the bullets are more of a piercing attack compared to the lasers which have more heat. And again, the uranium weakens v. 

If you go back to season 3, Homelander’s fights seem weaker than what he was implied to be. Destruction was minimal and he was slower than someone who can supposedly react faster than an explosion and chase a speedster. Well, soldier boy obviously also had the uranium which, by this same logic, also weakened Homelander. Not in a way that hurt him but just weakened his power levels. Now you might say “but homelander still seemed more powerful in season 3 than final fight of season 5” sure, but remember, Kimiko’s uranium is definitely better than soldier boy’s. Some Soviets limited by 1980s limitations gave soldier boy the uranium. Sage and Frenchie with better resources gave Kimiko the uranium. 

I also have proof that tentacles butcher’s mere presence weakens Homelander. In season 3 when Homelander’s lasers hit butcher, they KOd him for a bit. He got up much faster in season 5 after the lasers hit him, and he somehow evaded Homelander’s senses. A few episodes later, in the uranium room, Homelander is on his feet when butcher arrives, Homelander is worse for wear and he doesn’t muster the strength to break out of the room till after butcher leaves. Of course the scaling of Homelander>Soldier boy>=Bombsight (I personally have Bombsight beating soldier boy high to extreme diff in a fair fight but that’s a different matter)>>>Butcher would mean that logically Homelander especially with v1 should easily destroy butcher, but their actual fight showed something different. As for what about butcher’s presence weakens Homelander? I’d say it has to do with the cancer aspect of butcher’s powers. The tentacles seem dangerous not just in a melee way but a biohazard way. 

Also, Homelander truly flew to space and back in less than 3 seconds (I don’t think he actually did but whatever) then perhaps he weakened himself that way considering how the outlier of it. 

Finally, there is speculation that the v1 actually weakened Homelander or at least was bad and/or didn’t boost him. First of all, it could have been hit by soldier boy’s blast. Second, it could simply be too old and therefore corrupted. Heck, its effectiveness could have been lied about or exaggerated, etc the problems with this are Homelander’s feats post v1 but before the final fight. Well, consider a-train was way slower earlier in season 1 but after taking more v he got faster, but later slowed down. In this case, v1 could have similar effects of boosting earlier on but wearing off pretty quickly in the boosting aspect and having the reverse effect especially if it’s been corrupted (age, turbulence, uranium, etc) and if uranium being near v is enough to weaken compound v even in the most powerful supe, then it should be enough to weaken a substance in a mere syringe needle 

Thoughts?

What are your in universe reasonings/justifications for why Homelander seemed much weaker throughout the final fight compared to his feats prior to this fight? My reasonings in long text post: