step 1 - open the game and click "options" the first [default tab] is "gameplay" and "cross save" is the 4th tick box down... as you say they are the same characters i'm going to assume this box is ticked, personally i'd untick it while playing and then tick it once finished to then upload your saves so your network isn't working in the background while you are playing but thats me
step 2 - the third tab across says "video" it should list your actual Gpu not an intergrated chip and i want you to change the "Overall Quality" to "Medium"... once this is done hit "apply" at the bottom to comfirm the changes then see if the game still cashes when ever you getto the Hag fight
some other points;
you don't have anything installed to C drive because Windows doesn't allow that, it must be C folder so C Steam or C Games is fine... as long as its not c program files i.e, "program files" is the key words and you don't want things [anything at all] installed in there
you could disable onedrive or just move the game files out but i would do more testing before trying that
