Modi Perficio

I'd say it means Perfect Way or Perfect Model.

Modi Perficio would mean "Of the method I accomplish".
Sounds like something from an automated online translator,
if you don't mind my saying so.

The proper case for "modus" is nominative.
Verbs do not have cases. I think you want the third person singular, present
indicative active form, "perficit".

And don't forget about "that" and "which".

The method that accomplishes is modus operandi, plural modi operandi

Modus perfectus, plural modi perfecti relates to music and means the perfect way.