Looks like it's a 1990 MP21:
Think you called it here... it is an early enough model that it does not have a replaceable dropout hangar which is something that took manufacturers a few weeks to figure out and right after the first bike came back with a broken hangar that could be replaced.
It is like... what if Schwinn made an electroforged mountain bike as the smoothed welds are reminiscent of the old Schwinns, but it is of course Aluminium with the welds filled and smoothed out and in this era it would have been of Asian manufacture.