How about feature which already available on https://ninjastic.space/search? Aside from that, i would suggest these feature.
1. Sort by relevancy.
2. Showing message that the search keyword may contain typo (such as showing "bitcoin" when someone enter "bitcon").
Ninjastic is showing entire posts so it's impossible to find anything meaningful when you search for a keyword.
It needs to show only an excerpt with a link and title like forum search and Google do, it needs to have page numbers for browsing the results by page and most importantly it should not be looking inside quotes for keywords.