Nulled theme pros and cons

The cons are that you don't get any updates. So you're stuck with what you have. Plus the one who released it might have created some loopholes in it.

Long time nulled Worpdress / Prestashop themes and plugin / Codecanyon script user,
I get my nulled stuff from the most reliable nullers out there. Can't directly name them but they are not that hard to find, just research their world for a day or two and the best ones will stand out.
After hundreds of instances of using / tweaking / releasing and delivering to Web Design customers and more importantly hosting the scripts myself for them (secure cPanel / DirectAdmin nodes) I have never even once had a breach or incident, never had zombie botnets and resource leeching either,
I always lean on the safe side and since I know my way around PHP and JS I always inspect all the code but never found anything fishy and out of order.
You will be surprised by moral integrity of the nullers. Such an awesome bunch of dudes they are :-)

Make sure you check out the source. Pay extra attention to any javascript that looks encrypted.
For a serious website, do not use nulled templates.

Depends on what you want injected in your site I used one and got into a lot of legal trouble

For nulled, pay attention to the source code as it might open up your site to malware.

If you think it's worth it after testing, then buy it and support the devs

I mean if you're working on something really professional you should probably just pay for the sake of security.

Although if it's a small personal project it doesn't really matter.

I always depend on freedom, so Nulled themes good for me. Ans Nulledbb has good coding and design, just love it.

Null is very bad not good for testing i totally agree. there colud be hidden malicious codes hidden

no point in using nulledbb themes, aoki is going to change the base code to this theme and that will screw up mostly all other themes,

"leaked/ripped themes are called mirror themes they pull the css of nulledbb theme and impute it inside a .xml file which resembles the theme, once some codes are changed here that theme is broken."

the best bet is to use official mybb themes or hire someone to build you one.

Just like everyone said, the difference between the nulled and the not nulled are the security breaches, some nulled plugins do have a malicious script encrypted on them, and if you want to test things out to check you might do so.

Install a plugin that could check your website if it's secure or not and scan for the malicious script.