Stating that he came to fullfill means to apply the OT we have different meanings of it , BUT it does NOT indicate trinity in anyway
The royal we existed in semetic languages :
Of (c): the pluralis excellentiae or maiestatis, as has been remarked above, is properly a variety of the abstract plural, since it sums up the several characteristics belonging to the idea, besides possessing the secondary sense of an intensification of the original idea. It is thus closely related to the plurals of amplification, treated under e, which are mostly found in poetry.
Wilhelm Gesenius,
Gesenius' Hebrew Grammar/124
