Spirithost is a solid early game option, though one that we're really not going to want to take past 40. Can sometimes be 50 if we're really desperate. She does have a few issues. 

One of which is that remove debuffs/block debuffs is on a 5 turn cooldown and the other being that the speed aura is a small one at 10%, which will get outclassed by High Khatun once you someone gets her. Overall, the speed aura is solid and the increase attack is the best part of the kit. She doesn't really lend herself to account progression, though. You will end up being much more likely replacing her in a team before you will Warmaiden just based on needing to fill those team spots with champs who do more than Spirithost does.

Warmaiden does get outshined by the good defense down epics but there aren't so many that I would rank her below Spirithost as best farmable rare. Warmaiden isn't really meant to be a nuker so much as your defense down that you take up to 50 - and not past, in my opinion - who you'll pair with your DPS (starter and Ronda, these days) to clear waves in dungeons and campaign. 

Having a 60% defense down on a 3 turn cooldown is quite important and even though I think Warmaiden will eventually get replaced as most players core defense down option, she does the job well enough early on.

Warmaiden: I got Dhukk from a shard so Warmaiden became completely useless.

Spirithost: For example, I'm in Dragon 12/13. Both are 50, but I take Spirithost instead of Psylar. Psylar's tm control doesn't work on the dragon and Spirithost has decent survivability and saved my team a couple of times removing all team's debuffs/poisons from the dragon. And until I got Gorgorab she was my opener in the arena.

So you think Warmaiden, Diabolist, Heiress ... are all better than Spirithost? 

Was looking at it from a long term viability standpoint. Of course if you pull one of the S tier Defense down epics, then Warmaiden becomes mostly useless outside of Faction Wars and a Secret Room or two. :)

Warmaiden: Definitely better. Does something very important, can remain usable for awhile if we don't pull a better defense down. 

Heiress: Yes. Has the better speed aura in dungeons, Has the 1 debuff cleanse on a 3 turn CD with 30% speed boost for your team. She has the added benefit of being viable in late game Demytha Clan Boss teams, too. 

Diabolist: Close. I think reasonable kits in terms of usefulness but she can be used in Faction Wars - sometimes late too - for turn meter and speed boost shenanigans. 

Nom nom nom, y'all making me hungry talking 'bout all this food lol.  I agree with DT.  Warmaiden overall more useful for most accounts.  But if you pull Dhukk from your first few shards then yeah that's gonna kind of change your perspecrive.

Warmaiden is not as usefull to you anymore as she was before, because you pulled Dhukk. How can you generalize that? If you would have pulled Doompriest instead of Dhukk, you would still use Warmaiden and kick Spirit Host out of your teams instead.

I see people keep saying to only take certain champs to only 50.  I have kept warmaiden and spirithost at 50, but i don't feel like i have a lot of great options to take otherwise to 60.   (right now i have my starter, elhain and coldheart at 60).   Do you just wait until you get a really good one, and farm and stash food champs until then?

Spirit host over psylar? Lol.

You're not using Diabolist late game? Sir, look at all the value you're throwing away! She's the easiest champ to book in the whole game!!!! lol

I'm sorry to disagree with you. What does Warmaiden bring to the table? The Decrease Defense debuff.

Spirithost? The Aura, the Increase Attack buff and the remove debuff ability. Is it on a long cooldown, is the aura weak ...? Yes, if they were the best she'd be a legendary.

As I told you she has saved my team several times in the dragon, removing in one click 3x5=15 debuffs. Better than Psylar (and tested several times). Of course, she's not better overall, but I think she's better at least in the dragon, Psylar can do nothing with the dargon's tm, only with your team's.

You'll find that the value of debuff removal is significantly diminished as you continue to play the game, whereas the value of TM control is significantly increased.

2 turn Decrease Defense on a 3 turn cooldown? Far more valuable in early game than a cleanse and block debuffs on 5 turn cooldown. Warmaiden can hit hard if you know how to build her. 1300+ base ATK and 4x multiplier on the AOE? You best believe she was in my Arena squad until I got Stag Knight. 

I understand you pulled Dhukk early, so you take her for granted, but trust me, not many people are lucky to pull a reliable (100% chance to land) Defense Debuffer early in the game, and she is very valuable if you don't have a Decrease Defense champ.