There's a few and they're not actually called sketch pens or anything straightforward like that XD
These were all done by me doing a basic curvy stroke and then scribbling at the end (except for the first one because I didn't think about it then and I'm lazy >_>). Pretty sure the v) ones are all default brushes and the vb ones are from this modular brushset I can't live without XD
oh wow those look so interesting, imma go and play with krita a bit now ! thanks, fyn :D !!!