Kaijuu 8-gou

I can't fully explain but I'll try. both protagonists become the thing they are trying to beat. helped along the way by their male and female companions. Using their abilities to help defeat the enemy, which they don't know a lot about. 

Both about special military force fighting giant monsters while unveiling their truth. 

Humanity is being attacked by giant monsters. To protect themselves, people create a special squad that uses special costumes and weapons to fight monsters. The similarities of these anime stories do not end there. The action takes place in a world full of mysteries for both the viewer and the main characters. They are interesting to watch not only for the sake of battles, but also in order to understand the reasons for this war 

Same world environment, humanity surviving against powerful monsters that keep attacking. The main characters share a common mindset, and go through similar events on a personal level. 

A similar plot outcome of the main character to those with whom he fought / wanted to become 

Attack on Titan and Kaiju No. 8 share significant similarities, primarily in their central premise of humans fighting against giant, monstrous creatures where the main protagonist gains the ability to transform into one of the very creatures they are battling. The main character is a completely average person who has long earned to join this elite group, and actually manages to do so through persistence, hard work and determination and Both Eren’s Titan & Kafka’s Kajiu Does Have a Similar Design they similar looking teeth and Fighting Style 

Both World Trigger and Kaijuu no.8 have a strong sci-fi-esque ambience, and if you're into that aesthetic, I recommend checking out either series! But that is not the only similarity! In both cases, the city is in constant danger from monsters appearing, and the protagonists are specialized in defending the city. Well, that's a strong similarity! But wait, it gets even stronger: while the standard weapons depend on the individual's abilities and creativity, there are some rare personalized weapons, that require the user's compatibility and that are made from other people's sacrifices. So, if any of those aspects captivated you in one series, you might enjoy it in the other title as well! read more 

Similar sci-fi setting, militaristic organisation defending against city-destroying monsters. Both battle shonen with focus on hype fights and badass characters. 

An organization set on defending humanity. A very structured power system that allows for individual specialization and some wiggle room for anomalies. A hierarchy, ranks, recognizable faces. All while still mantaining slice of life and fleshing out characters, their motives and relationships. At last, a mistery pertaining the enemy forces and how they work. Kaiju N°8 is a faster paced, lighter and more fun version of World Trigger on a moment to moment's basis. Wether this results on a better show at the end of the day, is still up in the air. 

Monster beat-em-ups w/ supporting tech sci-fi weaponry. Debates on who is considered "human" or "allowed". 

An organization who fight against creatures, if like kaijuu no.8 you have to try World Trigger(very underrated and better) 

Main protagonists both get possessed by an alien form of life and gain tremendous power. They keep their humanity and try to use their new powers to help humankind. 

Both series dive into the thrilling concept of Humans forming a symbiotic relationship with alien species with extraordinary powers to fight against other alien monsters to defend Humanity.  

"Kaiju No. 8" and "Parasyte: The Maxim" share similarities despite their distinct premises. Both anime revolve around humanity's struggle against monstrous entities: in "Kaiju No. 8," the world is threatened by giant kaiju, while "Parasyte" features parasitic aliens infiltrating human hosts. Protagonists Kafka Hibino and Shinichi Izumi gain extraordinary abilities due to their encounters with these creatures. Kafka transforms into a kaiju, and Shinichi develops enhanced physical prowess. Moreover, both series explore existential themes, questioning the nature of humanity and identity amidst overwhelming threats. Their narratives are characterized by intense action and suspense, captivating viewers with their gripping storytelling and exploration of human resilience in the face of monstrous challenges.  read more 

A similar plot where the main character gets fused with one of the bad guys, but still wants to fight on the side of the good guys despite how much of a danger his existence is to society. Both main characters are also loveable optimists, and there's plenty of comedy spread throughout the series to balance the darker moments. (Well, for JJK S1 anyway.) They're both really entertaining battle shounens, but instead of special powers, Kaiju No. 8 has power suits and guns. 

Both involve the protagonist (who has a very powerful variant of the enemy monsters inside of them) joining an organisation that hunts these monsters. Curses and kaiju feel very similar (apart from the very human curses) and I feel like fans of both shows will enjoy the other, especially if they liked the aesthetic and fights of the other. 

A world were mindless monsters constantly invade, with an organisation made to counter the threat. The stronger monsters have higher intelligence, and the stronger fighters of the organisation are forced to fight these monsters. 

The main characters of both gain the ability to turn into a monster, then they join an organisation to fight monsters that pop up and kill people. Both are exciting, gorey, and filled up to the brim with silly humour. Both have outstanding animation. Both protagonists are quite overpowered, but not to the point where it stops being exciting. They can and will get harmed throughout their journey, but in the end will always come on top. Chainsawman is definitely the more silly of the two, with ridiculous and sometimes gross humor present in basically each episode, while Kaijuu 8-gou is more toned down in that regard. In Kaijou 8-gou Kafka always wanted to be part of the extermination team and had to try really hard for them to actually consider hiring him, while Denji was recruited... quite forcefully...  read more