So, I have plenty of consumables including draughts and elixirs, but they just don't exist in the maws of madness. My inventory appears to be empty, but I checked and I do have them. Why?
In the normal map (garden of the magnates in umbra forest, to be specific) OUTSIDE of battle, I can use the genetic thing but no consumables either.

I think I may know what your issue is with the Draughts and Elixirs, and in case my idea is the case, I'll try to explain.

Are you sure you're trying to use Elixirs and not Potions? While they look very similar, they are not the same and can be differentiated by their item description.

Potions are used solely from your inventory and cannot be used during battle. They do resemble Elixirs, but are shaped differently and if you read the item description, it'll tell you if it's a Potion, and if it is, it'll say "This cannot be used during a Battle" at the bottom of the description.

Elixirs on the other hand will tell you "This item is consumed when used" and can be used during a battle.

They look very similar, so confusing them is easy to do.

Draughts on the other hand can only be used if a pet is knocked unconscious. Even if the pet has only a little bit of health left, a Revival Draught cannot be used on it.
So if you're trying to use one and your pet isn't unconscious, it won't be an option for you during a battle. Only when your pet is unconscious will it be an option. Draughts cannot be used to heal a pet, only to revive one that's unconscious.

There's also cool downs between Elixir and Draughts usages. So if you use one and then try to use one the next turn, that won't be an option. You'll have to wait for the cool down to end, which it should tell you how much longer of a cool down you have if you try to use a Draught or Elixir during this time.

I hope this information possibly helps you solve your problem. ^^

No, not exactly. I can use neither elixirs or potions- both of them are unusable whether I'm in or out of battle.

Maybe message Krinadon and explain to him the issue you're experiencing to see what can be done about it in that case?

Oh, no, sorry, it's fine now. It was because I used the inventory instead of party manager. Thanks for your time :)

Ah, well I'm glad the issue was figured out. ^^