I've seen several native Japanese sentences, particularly in novels and music, where there are two words that both mean the same thing but are still used together.
My most recent situation is as follows: 「記憶のすべて何もかも黒に沈めて堕ちていく。」
「記憶のすべて」 is referring to the entirety of the speaker's memories. But why has 何もかも been added after? It is perhaps to add emphasis? Is there a way to translate it into natural English?