Sergei Lukyanenko’s works.

It's like they were replaced after the "Night Watch." He and Perumov are the only Russian science fiction authors I've read almost completely.

Both didn't just decline; they shifted towards popular fiction. This isn't necessarily bad; it's profitable, and people enjoy it. But still, if you take the early "Monday" by the Strugatsky brothers, you'll want to put the "Night Watch" series... far away.

There's a lot to criticize, but I don't feel like it. I love the early works of Lukyanenko; he wrote sincerely and with originality.