Manthika

When your skills from irl are exterminating a large amount of pests via poison and skillful methods that don't exist in another world: why wouldn't you become OP incredibly quickly by exterminating thousands of small monsters and gaining a ton of EXP without actively being in any fights?  That's the premise this isekai follows, as well as going along with most isekai cliches (harem of dumb girls and unnecessarily ecchi fanservice included) but it gets worse. 

The most annoying part, in my opinion is it repeatedly follows: 'situation' 'let's back up 24 hours and explain how I got in this situation' because it's a huge pet peeve of mine for things to be unnecessarily non-chronological.  Then there's the 'sudden hot slave that you now own' cliche (which falls into the harem cliche but is a cliche of its own, too) and the fact that it gets really boring really fast.