The violent thrashing of the leech monster's body produced two cascade effects, one of which helped Adam's cause, while the other was far more detrimental.

The good news was that the leech monster was distracted by its agony and temporarily ceased attacking the students, but the bad news was that as it was thrashing its massive body, it released a huge amount of mucus.

Adam was still situated where the leech monster's wound was, and as the mucus came crashing down, he had no time to dodge and was instantly completely drenched.

Immediately thereafter, his body began to sizzle audibly from intense corrosion.

The sound was extremely loud, and in mere moments, his entire body began to bubble and froth as if he had been tossed into a pot of scorching hot oil.

This is some nasty stuff! 

This was one of the most powerful attacks that Adam had faced to date, and if he hadn't undergone his latest evolution, he would've definitely suffered...