Cool. I haven't heard of Medibang before.
I've used free programs before though. I use GIMP a bit which is free, and I have use Inkspace before (also free) but I have Adobe for tertiary study anyway now so now I use Adobe Illustrator for some things, Photoshop for others and GIMP for others again as I find they all have different functionalities and some just work better for certain things.

My tablet is a Wacom Intuos 2. I got it second hand and it works fine.

I was impressed by your art. And I really like Overwatch. Just also interesting to hear about how things were done. Look forward to seeing more.