I usually do my best to be kind to people and describe all my ideas and possible solutions to their problems. 

At some point (I don't know when/how) I might have insulted someone, or at least I probably made him angry somehow, because for a time, I'm having a feeling that he keeps tracking my answers, and as soon as he sees one, no matter if it is useful answer or not, he downvotes it and starts to criticize with untrue arguments.

for example there is a question like:  
"how to eat soup?"  

as an answer I write:  
"if possible do it with a spoon, but if you don't have one, try drinking it and give a feedback."

short after, this person appears, instantly downvotes my answer and comments that this is such a bad idea and how bad idea it is to "drink it".  
I even saw him comment on other answers that "this is a much better idea than drinking" - (always the same person)

(sorry for my bad metaphor, best that came in my mind right now)

Even though I flag his comments and usually they are removed, it is not only weird but also annoying in a long term.

So what should I do to get rid of him, or make him stop?  
Already tried reasoning with him but I had no luck.

If requested, I can link some posts as an example.