The kinda “official” (?) answer about the Dyad (I don’t know how much you care about this, but still) is something like:
The Dyad is a natural phenomenon, not something you really can create. When Ben became Kylo and fought the previous leader of the Knights of Ren, Ben and Rey shared… something. It’s like she feels he’s falling to the Dark Side, meaning that they had a connection years before the movies (all this stuff comes from Kylo’s comic).
All other things that happen (Kylo probing her mind in TFA and Snoke mind bridging them) just enhanced something that was already there.