Usually combined with "go" in the present tense or "went" in the past tense to describe an unbelieveably cool or Matrix-style action. Sometimes involves quick reflexes (usually in dodging or blocking things), or violence.
"I went totally Matrix on that kid who tried to steal my cotton candy."
"Dude, stop fucking around or I'll go Matrix on you."
"That was so Matrix when you dodged that hot dog."