The icon is a Rash Fan Render by unbecomingname

Audio software used: LMMS

Plugins used (bundled with LMMS):

-Nescaline

-Sf2 Player

-VeSTige

VST used:

-Sforzando (https://www.plogue.com/products/sforzando.html)

-Metal-GTX (https://unreal-instruments.wixsite.com/unreal-instruments/)

Plugins used (external from LMMS, could be considered VSTs too):

-BassProfessor MarkII (https://plugins4free.com/plugin/2590/)

.SF2 Files used:

-Nice Bass Plus Drums v5.2 (https://sites.google.com/site/soundfonts4u/)

-UHD3 Soundfont (https://coolsoft.altervista.org/en/forum/post/4325)

-Undertale Soundfont (https://musical-artifacts.com/artifacts/914)