VegitoTy
Thanks for the chapter! I think it would be cool for him to try to create a breath after he learns some elemental breaths such as: fire, stone, water, lightning, etc... he could try to create an elemental breath that has the characteristics of all the ancient breaths and still awaken the mark
I don't think Gojo would really use a specific breathing, I gave him total concentration breathing just so he can be more efficient and be even faster and have more strength then he already is (for what though? I have plans for Gojo beyond him just "killing all demons and the story's over" ;) ). About the mark, I don't see Gojo getting something like a mark, especially in the demon slayer verse , since nobody will be able to make him break a sweat here.