I don't know much about Buddhist soteriology, but I think co-redemption would fit in very well there. Even if it's thought that Buddha is in some sense a primary redeemer, there's also the sense that everyone must come to enlightenment themselves, and participate in the same enlightenment which Buddha participates in.
I only bring up Buddhism for the sake of contrast.
I think there's a kind of Gordian knot in Christian soteriology, where we have a zero sum game: either it's my merits added to Jesus' merits, or it's Jesus' merits alone. The first seems to lead to pelagianism, and the second to quietism. Buddhist soteriology seems to cut that Gordian knot quite well by saying (to put it in our own terms) Jesus' merits and my merits are one and the same, since I am in Jesus and Jesus is in me. So in a mystical sense, when I repent and am saved, it's Jesus who's repenting and being saved in and through me.