It's blocking by user agent and source ip. You should be able to port the list easily for Nginx. I'd even say you can write a simple awk script in a few minutes to convert from Apache's format to Nginx's.

curl -s https://raw.github.com/bluedragonz/bad-bot-blocker/master/.h... | awk -F\" '/SetEnvIfNoCase/ {pattern = pattern $2 "|"} END {print "if ($http_user_agent ~ (" substr(pattern, 0, length(pattern)-1) ")) { return 403; }"}'

Not tested. :)

What "new search engine" has actually generated actual revenue for any webmaster in the past ten years? You could argue DDG but that's the only one I can think of.

The problem is that both Yandex and Baidu are rather poorly behaved - they hit your website way too fast, downloading large bandwidth files in quick succession. That's actually what led me to the bad-bot-blocker project in the first place. Baidu has also been accused of not respecting robots.txt though I have not personally observed that.

This is the reason they're blocked, not because they're new or non-English.