MAJOR XENOGEARS SPOILERS FOR THOSE WHO HAVEN'T REACHED THE FINAL DUNGEONHe was always the Contact, he gained that term when his first incarnation of Abel made contact with the Zohar/Wave Existence aboard the Eldridge 10,000 years ago, Abel reincarnates because he made a deal with the Wave Existence to destroy the Zohar. so Kim was already the Contact because he's a later incarnation of Abel. Just by existing in an incarnation, Abel's reincarnated selves are the Contact. Remember how in the flashback of Ramsus' past, Miang told Krelian she had already found the Contact, in the form of Fei as a child. So Contact is pretty much a term signifying the person was a reincarnation of Abel. Whether Kim ever made contact with the Zohar in his life is unknown.

The Contact you are referring to is that Fei's incarnations can re-establish Contact with the Zohar to gain their full power to destroy it. In Lacan's case, his mental state made doing this not work quite well and he basically became insane and used his knowledge of past lives to activate the Diabolos Defense units aboard the wrecked Eldridge remains to exterminate all life on the planet. The planet's major powers actually had to band together and use the Omnigears to fight them off and stop Lacan. This was the "ancient war with god" that Old Man Bal spoke about. Lacan didn't regain his sanity until he was about to be executed and so his soul reincarnated as Fei (presumably) and his will lived on as Grahf. Grahf wanted to destroy both Deus, the Wave Existence, and all human life in hopes of his and Sophia's souls could escape the Wheel of Reincarnation. Fans speculate that Miang helps him cause she too would also like to stop reincarnating but it's debatable if she even has a will of her own like Elly does. So it gets very Buddhist as well...