Make the four new fluid drinkable and give the drinker effects, when stored in tanks of Traveler's Backpack.
Here are my ideas:

• Mud: grant nausea and slowness;
• Liquid Crystal: grant regeneration;
• Midnight Resolution: grant wither and blindness;
• Dragonrot: grant life drain.

Drinkable = in bottles, you mean?

I'll see what I can do about that. Sounds fun!

Drinkable = in bottles, you mean?

I'll see what I can do about that. Sounds fun!

Emm...Not exactly
I mean Traveler's Backpack allows player to drink fluids in the backpack's tank, including lava. But...bottles of Liquid Crystal sounds even more fun!
And there is also a bug: when potions from Potion Workshop is stored into the tank of Traveler's Backpack, it simply becomes "No Effect" potion. I feel this should be solved by the backpack mod?

Tested on latest Spectrum Essentials.

Looks like there is!
Tiviacz1337/Travelers-Backpack#712

I've left a comment for them.

I'll check out backpack drinking, then.

Yes, the 'no effect' part would have to be solvrd by them. Sounds they just handle the default potions, ignoring potions with the CustomEffects tag (which is also a thing in vanilla).

I will open an issue in their repo later, if there's none.

Thanks lol.