Kaeya doesn't function just as a sub DPS. He's also a really great batter ... However, the generalist build for him would be 2 piece Blizzard Strayer and 2 piece Noblesse Oblige.

Even further, Kaeya is given for free at the beginning ... Instead, Shatter should be considered as free extra damage for his Physical DPS build. That said, it’s hard to recommend Freminet ...