[Galaxy S6 Q&A, Help & Troubleshooting] Starthz:
Hey guys, so I'm pretty new to all this, I wanted to root my Galaxy S6 - SM-G920F - to be able to play pokemon from home... yes, that sad. So I started reading XDA like my brother recommended and "learnt" how to root my phone. In the beggining when i was installing SuperSU I had some problems and my phone went into bootloop, but it was because of my cable, I then reflashed it with another cable and it fixed the bootloop issue. I went on to install TWRP and that's when mistakes started happening. First of all, I forgot to back up my phone, including the EFS which, after reading countless posts, I understood is what gives the phone the IMEI code.

I tried installing the standard Xposed on Galaxy S6 (only later on i learnt you must use Wanam on samsungs from S6 and above) and my phone went into bootloop, with out knowing what to do (i tried the uninstall zip but it was failing to install from twrp...), very stupidly, i deleted my System folder... After much more reading, i tried using KIES3 and Smart switch to recover, but they always ask for the stupid recovery code,which I don't have, when i tried the upgrade and initialization option... I tried costum roms and a ****load of stuff. Custom Roms would usually work, my phone would turn on and that's when i noticed my SIM wasn't beeing recognized. (later on i also found out i didn't have IMEI) tried flashing the appropriate MODEM for my galaxy but it all failed. I don't remenber all the stuff I did tbh... I tried the tyrannus ROM and XtreStoLite Universal Deodexed Mod Edition ROM, and tried flashing the MODEM that comes with the last mentioned ROM and yeah, probably just useless attempts that wouldn't fix the problem in the first place. Then i tried flashing Stock, from Sammobile: I bought my phone at the Portuguese vodafone, so G920FXXS3DPF5_G920FVFG3DPC1_TCL (marshmallow) with Odin but it would always fail. Then i read something about splitting the folder in 5 and flashing 1 by 1 and it would work until the Hidden zip, which would always fail. I tried not flashing Hidden and my phone turned on and I went back to stock although, still with out IMEI or baseband. Then after more reading, i found out the best solution would be giving it to a store.

So i just rooted, twrp and did what i wanted to do in the first place. With the correct Wanam Xposed this time (later on i found a way to hack pokemon with out root... sucks :v) and i managed this time.

Yesterday i went to the stored and today the guy told me to go get it, with high hopes i went there, to find out he couldn't fix the problem... He tried Octobox to rewrite the IMEI from the one in the back of phone, but he says it failed. So now I really don't know what to do. The guy went on holidays and told me to go back there when he comes back, we wants to try to downgrade to lollipop and try to fix it from there (he said he has more tools available to work with). It could work, Galaxy S6 just got marshmallow 1/2 months ago officially, and i bought the phone in october of last year, so maybe with the ROM it came with, I really don't know.

At this point I'm just looking for suggestions. I'll be paying attention to the forum and try to reply to all the questions you might have to my best. Thank you all for your time and patience!

:EDIT: so... another major mistake i guess, I found out today, by asking my parents where they got the phone, that the phone wasn't actually purchased in vodafone, the phone was bought in a Samsung store, so it is unblocked. So most likely I've been flashing the wrong stock rom all along. Could you guys guide me in the right direction from here?