Tony was a little older than average when he found his soulmate. Because his soulmate didn't exist on this planet until he came through a portal from a different dimension.
Imagine Tony getting deaged into a 5 or 6 year old, but instead of the team finding him, Bucky, still on the run and struggling with himself and the winter soldier, does. Bucky tries to take care of him, learning of all of Tony's issues and the abuse he went through. Eventually he has no choice but to come in and bring Tony to the avengers. After Tony comes back to himself they deal with the aftermath
Tony really hates magic. Has he mentioned that lately? He really, really hates magic. Nothing ever good ever comes of it. What he hates even more than magic? Portals. So when the two are combined, he really isn't happy. His point is proven when said magical portal spits of not one, but two, different versions of his father along Ana and Jarvis, young Aunt Peggy and his Mama. Things get... a little bit... interesting after that, shall we say? This may be a blessing in some ways, but it also a curse. It ends up being something else too - a way to finally lay some of his demons to rest, maybe.