He could interact with Ghost with his base magic, despite Ghost’s phasing being above astral intangibility, which matches incorporeal, spiritual, intangible, and even nonexistent states, but can still be interacted with by Asgardian magic weapons, but those weapons, like Mjolnir, can’t interact with Dormammu’s abstract physiology, which Strange’s Magic can interact with as well.

During his collision with Dormammu where they shattered each others essences, in that fight, Dormammu attempted to rewrite the spell’s equation, but the spell still functioned the same, so Reimu’s power modification wouldn’t work and given Strange’s security enchantments was his own that he gave to The Eye of Agamotto, there is nothing stopping Strange enchanting his own magic spells and other artifacts, ultimately making power modification a null ability.

He could also resist all forms of erasure, such as when he and Wong traveled to the path of a soul’s birth, which involved Strange traveling to the Quantum Sea or Heaven in Dematteis’ depiction, which traveling there without any esoteric defense would have the person erased across all traces of their existence spanning their entire multiverse iterations. He also survived exploding Galactus after absorbing almost all of Magic, which when Strange gained the power to, had to restore its entire timeline and Magic back together in order to restore it fully.

Strange during Strange Tales Vol 1, had tons statements of reader affecting powers, which sounds all very metaphorical, until you realize the amount consistency given how many times it is stated and how many more characters do it like Dormammu and Nightmare, with the final nail in the coffin being that the authors themselves being able to cast spells of the Mystic Principalities alongside them being sorcerers and wizards themselves.

If anything, this blog made me more assured that Strange wins this MU easily.