Funny story, is that I seem to have the opposite issue.  Out of the 8 legendaries that I have gotten from shards, 3 of them are from demonspawn, which is just under half.  Despite there being 16 different factions complete with legendaries, I seem to keep drawing from demonspawn.

Welcome to the RNG friend.  

@OP Maybe Plarium will add a FREE Demonspawn Legend to daily Logins and you will not have to suffer the horrible chance(RNG) odds of pulling a decent champ from shards

Oh but wait......hhhmmmmmmm. I am told the community Hates guaranteed things  in this game so better  keep your fingers crossed

Even if the next champ will be a demonspawn one (what we don't know at the moment but it could be...) it will still take few months to get it since we only have to complete Cleo first and after that  we will start getting fragments for the next champ.

During this time - about 3/4 year - maybe even longer, i haven't done the maths here - there are chances to be able to fuse at least  a fusion epic from the demon faction, or which faction ever. We just had a good one - Magnarr. Or get one from a shard...

I have the same issue with High Elves.  That's just the RNG of the game though... going to take awhile to do some of the faction crypts, and some of them you might end up making lvl60 rares to do.

I'm not asking for a guaranteed Champ, I'm not asking for a Daily Log-in prize, would be nice but just put them in the dungeons, in the campaign as a possible drop. That is it. instead of just throwing them in with the summoning shards. There are only one or two, I think but I could be wrong, or maybe a couple more that drop somewhere as a drop prize. Seriously, a 1-4 out of how many Demonspawn Champions. Less then 10% chance to get a Demonspawn on a Summoning Shard. WOW!!!! What great odds to get a Champion from Demonspawn. All they have to do is on in and change some code to add them to the Campaign Drop loot or tweak some numbers to up the drop percentage of the Summon Shards. Thats it!!! I bet someone in their development team has said the same thing and has some code they could drop into the game code and be done with it. SO...............Why don't they do it?!"!"!

In time you will have plenty of champions from every faction. Just use shards during 2x or 10x events. This game is a long grind and everything takes time, bit in time you will have a large roster. As well as way more champs than you will ever even be able to level.

I know you end up playing the "Long Game" over time, I get that because I've been playing it for a long time. The issue is the drop of only a few of the Demonspawns in the Campaign and everything else is from Summon Shards. Which if you look at it is a really, Really, REALLY crappy draw percentage. I've been playing this game since it pretty much came out and to only have 3 Demonspawn Champions in that time is stupidly dumb precentages. Nothing in that sounds like a good mix for being fair.

You play this game since it came out (round about 3 years ago), so you should have got Diabolist from campaigne and Tainix from from daily login-rewards. Together with the 3 champs you pulled from shards they are 5. Congratulations, you got your first demonspawn faction war team.