Unity ceremony including adoption vows

So, my FH who is my kids' soon to be dad and I are including the children in a special 5-candle unity ceremony, and we want to make vows to the kids during the lighting of each of their candles. His commitment to them is especially important as they've come out of a long and broken story, with bio dad abruptly ending his relationship with the kids. And even though I've never gone anywhere, I still want to reiterate to them my commitment to stay with them no matter what. We haven't talked it over a ton to get ideas, but i thought it could be good to see what folks suggestions might be for that. And the wedding day is rolling in like a freight train, only 3 weeks out. The adoption is a pretty recent development, but one that ultimately we're happy about, and the idea of including vows to them came out of this.
My thoughts were to reframe some of the wedding vows we make to each other to be applicable to the kids, in language that they really will understand. Kids are 10 and 5 respectively.