i don't know what to do i'm can't kill King Desius he's to strong is there something i'm missing out or something I can do to get around it? cuz it sucks when he can like 3 or 4 hit my pets dead.

Rainy-
Firstly, find better gear and stat layouts for your battle party. Your current gear is between levels 30 and 0, but all three Griffis can equip level 50 gear. There's often gear set on the trade broker, and there are also players who have spare gear they can give you. Take Noon, for example.
Noon appears to have a build based on a magic tank. However, his health stat, one of the most important for a tank, is much further below Goddess of Health's, who is more statted to be a physical cannon.
His gear is out of place, too. His relic boosts both Magical and Physical attack, and is built for a physical cannon, which he is not. His armor is for a magical cannon, and his level 0 bracelet is crafted for a magical cannon as well. So for Noon, put level points mostly into Health and a bit into Agility and Intelligence, and place him in the center of your party, AKA the first slot. Put Proficiency Points into Agility and Intelligence as well, and use either the Light or Dark proficiency trees, as they are magical tank-based trees. Also, go for Relics that increase Magical Damage, and equipment that increases Health, Agility, and Intelligence.
Second, check this thread out: https://www.sylestia.com/forums/?thread=622. It's one of the bigger threads based on the Tomb of Desius.
Good luck with your battles.

Now with the new system - which element would you suggest to attune your pets.

Right now at fire, considering air.

Thoughts?

Mine are personally attuned to Earth, Fire, and Air. I haven't really tried using the other types, to be honest.

Have not considered Earth - TYVM!

No problem!
But if you do use Earth for a tank, make sure to up Health. It doesn't have health-regen natural abilities like Shadow does, only with Leeching Strike at level 30(which has a four-turn cooldown), and instead focuses on making the target attack the tank, which can do serious damage if you're not properly statted and/or equipped.