I recently built a deck with one of the six cards which has no faction but needs three bases to play.

I then made a practice game and built two mountain folk bases and one Dark Legion base.
I then found out that I couldn't use the card mentioned above!
That was a bit unexpected because(although they weren't of the same faction) I had the three bases which is what the card requires, and the flux to cast it!

It is hard enough to play two or three factions already:
A) You are usually limited to cards which only requires one or two specific faction bases to play them!
B) Playing two or three factions means you have to play decks with a lot of cards!
C) You risk getting stuck with cards you can't play due to lack of faction buildings.
D) Your start is usually a lot slower than your opponent's, so you have to be able to decrease the opponent's lead.

It should be possible to use any base as one of the undefined bases needed to play cards without faction! Why? Because a full faction deck only requires the exact number of bases to play cards without faction, should a two/three faction deck require additional bases to do the same thing? That doesn't make any sense to me!

This is the reason why I believe there is a bug with the cards without faction that require two or three bases to play.

They used to be playable, I think they can't be played because of something I've noticed that was recently changed.

You can only play a factions creatures around that factions base.
So when you play a mountain folk creature, it won't let you play it in the dark legion base control area.
Since they technically have no faction, they have no control area to be played in.

Hopefully that's just a bug and not a gameplay change!

Zwidar: Usually you can play the unaligned units by any of your bases.

Yeah I can see changing unaligned cards to require X level of any combination of domains. The way it is now is kind of a hold over from an earlier leveling structure where it was much easier to get to level 1 than 3.

Any particular reason why I can't play a Dwarf next my Graveyard?

If I'm playing two factions, I don't see why I can't play a unit in any of my controlled spaces, doesn't make sense that it has to be a controlled space of the same faction.

Well were you can build guys is another thing that you have to manage. There has to be some disadvantage to playing multiple domains.

Anyway the unaligned thing now takes the total of your domain levels. So you can cast 3XXX with a grove and 2 graveyards.

The disadvantages comes from:
Not being able to reliably use 3 domain cards. When you have to split buildings between two factions it's spotty if you'll ever get 3 domain of one kind out at the same time.

Also having a hand full of cards of the opposite alignment that you have. There are lots of times I'll get a building of one faction, yet just about the rest of my hand is the opposite faction so I wind up discarding a lot.