BD can combo into his level 2 to get 1-2 kills from the get go, then go for another kill when they respawn.
No Dante can help big daddy also, when BD uses he's lvl 2 while Dante has not in a combo then it's 2 easy kills
BD works well with almost any combo fiend in the game. My friend and I rolled BD and Kratos and won plenty of matches.
BD definetely holds your opponents in place with down+triangle in which Kratos is clear to use his lvl1 without fear of missing or interupt. Since he builds ap fast to....that is a lot of kills.