I've got Kael 6 star heavy hit 35k AOE but need to progress in someway

Help for what ? If you want to ask that which hero need upgrade to 6*, the answer is obvious, Scyl 

thank you

is there an easier way to get epic and legendaries

Asides from opening your wallet and paying for them, you might want to have a look at fusions. They are the most easy way to get legendaries and epics in the game (in my opinion). But you have to plan ahead and save ressources for them. 

If I look at your rooster, it might be best to concentrate on progression (campaign, FW, DT, missions) collect the shards in those categories and wait for x2 events to pull the shards (or better: x2 events in fusions).

But an easy way to get higher champs? That would be paying and hoping for good pulls...and it leads to the Dark Side...

Also keep an eye on the permanent fusions (Rhazin, Relickeeper and Broadmaw), keep the champions necessary to fuse those since all of these fusion Champions are quite good at the beginning. Rhazin will stay good even in endgame and Broadmaw will help you finish the lizardmen faction some day.

buy the drexthar fragments

be patient and enjoy the journey with champs you have

Scyl, Apothecary, Armiger and what you already have will get you to dungeon level 20s

Better gear is your solution not shards/more epics & legos