Use QGIS expressions with [Geometry Generator][1] (for visualization purpose only) or [Geometry by Expression][2] (for actual geometries) - [see here for more details][3] about both options.

Use this expression, replacing `slope` and `aspect` with the names of your attribute fields:

```
project( 
	$geometry, 
	slope,
	radians (aspect)
)
```


  [1]: https://docs.qgis.org/3.22/en/docs/user_manual/style_library/symbol_selector.html#the-geometry-generator
  [2]: https://docs.qgis.org/3.22/en/docs/user_manual/processing_algs/qgis/vectorgeometry.html#geometry-by-expression
  [3]: https://gis.stackexchange.com/a/392619/88814