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For bosses, the easiest of the best digimon to breed against them is Nidhoggmon (Orochimon spawns at the swamp map, I believe). 

From there, against Diaboromon, you can use Flymon, Jesmon and a freezing leader like white antylamon and blue numemon (white antylamon spawns at the snow land). 

You can use freeze or low memory itens on your attacks. And chain paradox looks like a teal mist with a dark blue ball inside, if I remember correctly.