I want to eat Planacardia.

Hi, this is my first time asking here. I've been a very casual Honkai Star Rail player, dropping and picking it up again more times than I can remember. Even so, I'm enjoying it now. Recently, for the first time, I have a decent team consisting of Saber, Dang Heng, Terravox, MC, and Sunday. So, for the first time, I'm actually playing the game and not just surviving. My previous team was Welt, Moze, Argenti, and Gallagher. Don't ask how it worked... BECAUSE IT DIDN'T. So now I'm playing more often. The only completed planets I have are Herta Station and Jarilo VI. With the recent announcement of Plancardia, I now want all the characters on the track, both announced and unannounced. My question is, is it possible to unlock them all? Do I absolutely need to buy a pass and a blessing? Right now, without complete exploration, without the mission being finished, and with more missions to do than I have the will to live, I currently have enough jade for one pity, so I'm guessing that by finally doing everything I'll at least have the guaranteed one? I never went into detail to understand how the probability works properly, I don't even know what the sub-pity is... Thanks for reading my ramblings, and any advice is welcome!