I have 20 different scales of independent items (psychological variables, Big 5, beliefs, attitudes, cognitive abilities, all metric)
From theory I know they should all influence the dependent variable (score in a test, also metric)

I would like to find out which variables explain the variance between the scores of the participants best.

Ideally I would like a table stating:
Item F accounts for xx % of variance
Item G accounts for yy % of variance...
and then the cumulative variance explained by the top, items.

As for a diagram, to visualise I would like something like a scree plot depicting which factors are worth looking at.
In my imagination it would look something like Principal Component Analysis, but in order to explain a dependent variable.

Does something like that exist?