I believe this is a reference to the Finnish metal band Finntroll, who sing in Swedish.
It must be, right?! This makes me so happy.
I was very happy to potentially understand a reference, for once.
Or when Finnish people troll the Swedish ice-hockey audience by singing "Den glider in", a song they 'stole' from the Swedes in 1995 by winning the world championships in Stockholm against Sweden. Dunno lol.
So is "en del" often used to mean "some"?
Yes, it's pretty common.
Kan man säga "en del av"?
How is this different to "en del av oss"? I mean why don't we need " av " here?
I can especially recommend two songs from Finntroll: Jaktens tid (the time of the hunt) and Grottans barn (the children of the cave)