So I'm looking for any cultivation novel where the MC uses illusions for his offense and defense, that should be his main Dao. The kind of illusion master that even cultivators at a higher cultivation level would have alot of difficulty seeing through MCs illusions.
" The Last Dragon in the Cultivation World " The MC in this novel fits your description but idk if this is the one you're looking for.
A bit of a spoiler but Lord Xue Ying. Its his main ability in mid-end story. All his abilities combine into mirage dao later on, which allows him to immerse his enemies in a fake world/ leaving them defenseless in the real one.