Tsukuyomi's envoy activated the ruptured medicine and seized the opportunity to take control of Fubuki, Tatsumaki, and even Psykos's bodies.
Tatsumaki suspected that there was a Tsukuyomi spy disguised as one of Fubuki's friendly associates. Indeed, the Tsukuyomi spy turned out to be a new member of the Blizzard group.
2. Saitama dealt with all the monsters
After subduing Fubuki, Tatsumaki, and Psykos, Tsukuyomi's envoy immediately released the Demon-level monsters to replace him in finishing off the three girls. This threw the members of the Blizzard group into immediate panic, as they couldn't escape or rescue Fubuki's group.
However, something surprising happened. Those monsters were sent flying into the sky by a punch from Saitama, after he accidentally fell right into their cage.
Not only the Blizzard group, but also Tsukuyomi's envoy and his associates were stunned by this moment.
3. Tatsumaki defeats Tsukuyomi's envoy and successfully protects Fubuki
Seeing that Tsukuyomi's people were distracted by Saitama's actions, Tatsumaki tried to escape and initiated a counterattack.
First, she copied Tsukuyomi's envoy's psychic signal waves and detected the presence of the drug in her sister's body. Then she immediately twisted that into a shape thinner than a hair strand. Not only that, Tatsumaki also extracted it and threw it back at the Tsukuyomi's envoy.
Afterwards, Tatsumaki trapped this man in a sphere she created from the rubble of the building. In doing so, the professional heroine saved Fubuki and simultaneously protected Psykos.
Facing this situation, Tsukuyomi's spy infiltrating the Blizzard group intended to escape, but was captured by Tatsumaki.
4. Tatsumaki scolds Fubuki and her group
Seeing that Fubuki was rescued, the members of Blizzard wanted to approach her but Tatsumaki immediately intervened.
Tatsumaki felt that Fubuki's constant association with the chaotic group only gave the enemy an opportunity to exploit her. The recent incident was a perfect example. Tatsumaki demanded Fubuki to sever ties with her friends, as it would be troublesome if they exploited Fubuki's weaknesses again. While her psychic's assessment might be reasonable, it seemed a bit excessive at the moment.
After the Blizzard group opposed Tatsumaki's opinion, she became angry and intended to attack them. She even planned to injure the Blizzard group heavily so they couldn't be heroes anymore.
5. Saitama intervenes Tatsumaki
Saitama also thought that what Tatsumaki was doing was going too far, if only to educate her sister, and wondered why heroes had to fight each other.
From there, we can speculate that the showdown between Saitama and Tatsumaki may unfold similarly to the webcomic version.