These days tankie is used to describe anyone left of Hitler depending on your agenda. The term is meaningless. I reserve judgment because I don't know what you did there.
is a perfect example of a tankie. Constant and unironic support of Russia, an whenever their current imperialist and authoritarian efforts get brought up the response is "well the US is worse". They post hundreds of times a day. They constantly think they are here to "debate", although they are genuinely not actually capable. They think they want to see something like the USSR come back, when in reality they are a highly paid software developer living in Toronto, and they can only have this kind of opinion because they live in a western democracy.
They are the authoritaian left equivalent of a libertarian or Trumper, but realistically they are just dorks with no grounding in reality.
Scan through his comments and it will become clear.
@Pinklacey "tankie" is slang for someone who uncritically admires and praises the Soviet Union, Red China, or their modern equivalents (i.e. Russia and modern China, even though they cannot reasonably be called "communist")
The Communism part seems to be mostly a red herring, it's added flavor at most. The central core tenet seems to be an anti-American standpoint with whatever authoritarian/dictatorial regime that fits it. Seemingly regardless of political alignments, and regardless of contradicting views from what they claim to represent.
They often purport themselves anti-fascist, but this can be viewed much the same way as the DDR called their Berlin Wall an "Anti-Fascist Protection Rampart".