You're not really asking the right question, which probably is what is leading towards this being challenging for you. This isn't a game of "use these people everywhere". Just about every piece of content lends itself towards having champs specifically dedicated to being used there. I probably have something around 150 level 60 champs, and at least half of those see regular use somewhere or another.

So, the better question to ask is "which of these champs are best suited towards overcoming ____". And what that is, is for you to determine.

Judging by how you have only five level 60 champs, I'm thinking you're probably pretty early in the game. A good early-game milestone is Dragon20, and, judging by the aforementioned five you've chosen, my guess is you can probably handle that already. So, your next objective should be to work on a CB team. Getting at least Nightmare chest is a huge milestone to reach.

To that end, I would expect your initial CB team will be:

• Blind Seer (block debuffs)
• Giscard the Sigiled (DEF up)
• Stag Knight (DEF down, ATK down)
• Pestilus (leech) - turn A2 and A3 off. Not ideal, but you don't have many great Leech champs. If I missed anyone in your list, feel free to put them here instead.
• Kael (poisons)

If you're able to fight against void-affinity CB, you'll want Giscard to be slowest, and you'll want to have Blind Seer use her A2 on CB's third turn before his stun. If you have to fight against one of the specific affinities, you'll want Blind Seer to be slowest and use her A2 on CB's second turn, and you'll want Giscard to be second slowest. Everyone should be between 170 and 189 speed. There's a lot for you to learn about CB, so I'd suggest reading about how speed tunes work and then ask questions if you have any.