I found Dan-Elias’ channel (“synth000“) on YouTube purely by chance. He does a lot of covers in “a capella” style, that is with no instruments. Using his voice to cover everything from rhythms to beats to (obviously) vocals, with multi-part recording then layering it all together is pretty impressive.
Well worth a scroll through his various efforts as he’s covered songs by Dream Theatre, A7X, Slipknot, DragonForce, Cannibal Corpse… Give him a like and a subscribe if you enjoy his work. Hell, he accepts PayPal if you want to buy him a beer!