Finally rooted Calamity. It took a really long time from me, at one point tried to search everywhere for hints, tips, etc. luckily didn’t find any and was forced to find out for myself and learned a lot on the way 
But as it took so long i started to wonder how does this machine compare to the ones in OSCP?
If this would have come on the test there is no way i could have completed it on time and yet now that it is done , others like shouldn’t take as long…
well, learning something new is always like finding a treasure, the difference between htb and oscp, in my experience, is that oscp-lab is like a real company intranet and sometimes some information in a machine must be used to access in an other system, and u can practice pivoting in different levels, but many htb machines are way too difficult then oscp, like calamity.
some .htb machines are more difficult because they are updated with windows10 patches etc instead of windowsXP and windows7, new versions of Linux etc while the OSCP is not
Calamity is much much harder than anything in the OSCP but also focusses on a different set of skills. You won’t really be doing any binary exploitation or reversing in the OSCP.
Ok, thanks for the info!