Hey SOooo I saw that you were looking for Dom mamaguro x toji art and I found it but it on rul#34 And it goes by the name ijessbest (artist name) but they only made two art work of Toji and mamaguro,(they do more art but different anime) and I dont know if this is the one your talking about😅 but hope you like it 😚
Bye hope you have a great day!