I read some articles, and seen some videos about a github project that does this sort of thing, but it's a little bit outdated. I wanna see if this thing is possible to do, nowadays?
You can use your Android device as a Drawing tablet like Wacom Devices with the following options:
The GfxTablet project is an Android app that allows you to control a virtual Network Tablet on Linux, in this case in Ubuntu. (Last release: 19/Nov/2018, not maintained anymore but it is worth to try).
SketchBus turns your mobile device into a drawing tablet, it is easy to set up, very precise and cross platform (Linux, Windows, Mac, iOS and Android).
RemotedroidServer, just install the client on your tablet, and then connect to the local IP of your running server. It sends mouse movements, left click, right click and keyboard strokes. The server doesn't require installation, is a simple ".jar" file. You can run it executing:
java -jar /path/to/RemoteDroidServer.jar
Telepad, it allows you to control your computer remotely from your smartphone.
Slide App, it allows your Android tablet to be used as a Drawing tablet for graphics designing on Linux, in the description of the video you can find all the links to download the app.
Hope it helps.
There is a solution now: Weylus. Screen mirroring, pressure sensitivity and multi touch is supported.
Instructions for installation and running can be found in the readme, make sure to follow through the instructions regarding uniput otherwise things like pressure sensitivity will not work.
Disclaimer: I am the creator of this project.
You can use NoMachine software: https://www.nomachine.com/
It is a kind of desktop sharing software. I actually saw this question when i was looking for myself, but on the way I also remebered about NoMachine.
I just used it for ONYX BOOX Note Air, and it works surprisingly well.
You install android client and linux client (works also for max&win) and you can even connect from remote networks.
Although when both devices are on the same local network (say same wifi router) and you connect using local connection, the speed will be better.
For details check the software instructions. This company seems to be pretty good with both product and support.