Download and try these procedural shaders (in some cases I've used geometry nodes too) to create a bunch of VFX with a 2D look. You can find node groups with some exposed parameters that allow you to customize them.
The shaders work both in Eevee and Cycles.
They are all in the same scene, so if FPS drops, try to hide before "GEOMETRY_NODES" and "VOLUMETRICS" collections if not used.
Some of these are rigged also, you can tweak shaders or meshes with the controller nearby.
To make them work also in Eevee, I've clipped the start and the end of the volumetric settings in the render panel, so if you don't see anything, go back, or get closer!
Or switch to Cycles to have a better sampling without distance limitations.
Below some previews
Take a look into the node groups, inner nodes are grouped with frames for better understanding.
I'll keep updating this file and adding other VFX in future.
Scanned model by https://threedscans.com/uncategorized/dragon_1/
HDRI in the file was downloaded by hdrihaven.com
Some of these VFX are inspired by other amazing artist like lateasusual, check his profile on gumroad or twitter.
Tested with Blender 3.2.2
You will get a .blend file with a bunch of procedural toon VFX