Your champs are way better than mine. You have at the very least a team that can beat dragon 20, depending on the gear. Basically a rare team can beat level 20 dungeons if they have the gear, maybe even uncommon ( don't know if that's been tried ) So you have the champs. Tayrel, Karl, is that Altan, scyl. I'd say it's more to do with gear. 

ok thank you, so you would suggest focusing on what gear to put on thoes four instead of new champs

Defintely, I see you also have a royal guard which will be very helpful against dragon and the waves in the later dungeons ( 17+) The bottom line for this game as I see it is that it is mostly about the gear you have. An SS tier champ in bad gear is as useful as a common. Gear up one team to take on dragon. So Def down, attack down if you have it, poisoner, healer and reviver and a nuker for the waves, create a team that has all the attributes yoy need to clear the dungeon and then progress as far as you can. Then once you have reached as far as you can get consistently.... stay there and farm it until your gear gets better and then move up a level.

You have all the champs you need to clear Dragon 20 and probably some others too once they are geared.

So...

Tayrel - Def Down/Atk down and stun

Kael - Poisoner and help with waves

Reliquary Tender - healer/reviver

just because they have a blue border does not mean they are bad 😀

Yes- Dragon 20

Scyl

Kael

Reliquary Tender

Tayrel

Royal Guard

The gear you get from Dragon is monumental to help you through other areas of the game- lifesteal, speed, and accuracy

thanks for the advice! i have always had trouble knowing what gear to use, would you take a 6 star  uncommon or rare  artifact over a 4 epic or legendary artifact even if the 4 star had good stats ? that has been my delima with switching out gear.

another thing i have been doing is using the gear i have acquired from ice golum because it is the only stage so far that has givin me the potential of pulling a 6 star artifact, but would my energy be better spent grinding dragon?

Which dungeon you choose to farm does not matter all that much in the early and mid game, most of my champs are wearing broken sets... it's the pieces that you need not the set bonuses in the beginning so farm the dungeon that you can get highest on and just keep going with it. It'll take a while but eventually you will get some good gear appearing. Higher stars usually is better but you won't be getting common gear from dungeons anyway. For now you'll be looking for def% chest, crit rate gloves on attack champs or hp% on suppport and speed boots. Don't go wasting loads of silver rolling them up to 16, take them to 12 at the most until you get a really good piece you will keep for a while.