“Tankies” is slang for communists who align with the philosophy of authoritarian rule, like the Soviet Union who used violence to keep countries under their control in check.
Sealioning is something I saw a lot on Reddit, but not so much here - it is when someone responds continuously asking questions, trying to seem like they are engaged, but in reality they are trolling you. Like when you say something like “The sky is so blue today” and the come back with “That is interesting, do you have a link to some information that I can learn more about that?”