You might find my words also rude...but I just want to come directly to some problems.
Before you continue to level champs and gear, I would advise you to read Minin's comment and do some research.
I am just listing several points, you might to investigate:
1.) Basic concept to build champ
There are some beginner guides and tutorials on Youtube, Discord and so on. They are easy to find and will give you some hints on how to build your champs, how to equip them. A nuker should have 100% crit rate and as much Attack, Crit damage and speed as he can get (see comment of Ophelia)
2.) which gear to level and which to keep
There are also some tutorials about this. Basically with multiple champs on 60 you should be able to farm dungeons for better gear. Run Dragon for weeks or months until you have good gear. Looking at your Kael, the gear he has would be fitting for a very early game character (except for Ring and Helmet). Basically, you should aim for at least 5* and at least blue items, which you could farm in the dungeons. Forget about leveling other champs at this moment, farm dungeons. Level 13 would be good, as you have the chance to get 6* artifacts from them. In case you cannot beat them yet...there are guides on youtube easily to be found..
Generally...don't level up anything less than 5* to level 16...just a waste of silver. Farm Dungeons and you will get better gear.
3.) Which champs you should bring up to level 60:
For sure you will have noticed that bringing up a champ tp level 60 is very expensive regarding time and ressources. Choose your champs carefully...from the rooster you posted, you have many champs on level 60 which are just a waste of time. You have every starter champ at 60...Kael even twice. This is a waste of ressources...you do not need that many. Scan your rooster and bring up champions which will help you. On a first glance and your current rooster, that could be champs like Scyl (one of the best legendaries you'll get for free!!), Magmarr, Lanakis etc......before leveling up a champ to 60, check on Youtube, HellHades, Ayumi or whatever else source you might have whether the champ helps you or not.