In many cases, it is legal to read manhwa online if it's from authorized and legitimate platforms. But reading from unauthorized or pirated sources is illegal.
Another must-read manhwa in 2020 was 'The God of High School'. It combined exciting battles with a compelling narrative. The diverse characters and their growth throughout the story made it a standout.
Well, 'Lookism' is a top manhwa novel. It deals with themes like appearance and self - identity in a really interesting way. 'Sweet Home' is also highly regarded. It combines horror and survival elements in a post - apocalyptic setting. And 'Noblesse' is a classic. It has a great story about a powerful vampire awakening in modern times.
Some online manga forums might have links to 18+ manhwa, but it's important to note that accessing such content from unauthorized sources can have legal consequences. You could also look for officially licensed platforms that offer age-restricted content.