Its a balancing act so if you are only upping the temperature to get higher flow but not the speeds to use that higher flow then there will be some issues. Each filament also has different temperature and flow characteristics so just because the new filament works with the current settings doesn’t mean the old filament was junk.

The volcano was made for high volume prints and has a bigger melt zone. Ideally it’s best for bigger nozzles, high layer hights and faster printing.

If you want to print small and detail a normal e3d or other hotend gives you better control. For smaller characters you can use a standard hotend with a 0.3mm nozzle and switch on arachnid or similar in your slicer. That will give you pretty good results provided your cooling is good.

For calibration its best to watch a few videos as its a lot to discuss over a post like this. But you are looking to do e-steps, flow-rate, temperature tower and retraction. Also know that this may change when you change the filament or speed you are printing at so try and keep things as consistent as possible.

To be honest the Volcano HE is the wrong thing for printing small detail like a DnD character. If you do all the calibrations it can print quite well but will never have the control thats needed for high detail prints. Your best bet is to have an extruder setup that makes it easy to change out the HE. I run both the volcano and normal E3D v6 and swop them out when needed with a EVA extruder.