I give it a 3/10, the items are good but they don't go well with each other. I would loose the physical weapons in favor of a multi-use 2-4 range weapon and the switch the legs with massive lava feet if come across a pair. If you could show modules and drone I could rate your mech easier.
A lot of legacy items have shared the same fate, but I don't think we're going to get a mythical version of any items that only go up to legendary. But I do think it would be nice to have diamond shell back, or at least a mythical version of golem.