The sixth prompt is actually one I've been looking forward to on this round, the liquid sword. No, we're not talking ice, as that would be a cop out.
Unless you're freezing something that would not normally be a solid and be able to maintain this, such a thing wouldn't be possible. Believe it or not, the Monster Manual actually comes to the rescue a bit with this one. There is an entry for a fiend called the Ice Devil, who hails from the frigid layers of Hell called Stygia and Cania, according to 5E lore. While the description has an icy spear as their weapon of choice, who's to say the spear can't exhibit the same properties as the following sword?
One of the nastier materials we have on hand is elemental mercury. Acute mercury poisoning will result in a physiological response from the body in attempt to expel the material via coughing, nausea (may even cause vomiting) and hemorrhaging as the body does everything it can to remove the material. Chronic poisoning can look like any myriad of neurological or gastrointestinal diseases, even skin diseases. Without testing, you're looking at a very painful way to die if you suffer exposure to this.
And an ice devil can use this to shocking degree.
Due to their innate magic, a mercurial blade will be solid so long as the devil is alive and wills the weapon to remain. Once dead, or if they will it to be so, the blade will revert to its natural form of a liquid as soon as it gets warm enough. The freezing point of mercury is -40 degrees. (Fahrenheit or Centigrade makes no difference at that magical number.) On striking flesh, it will cause frostbite and melt a bit of itself into any wounds dealt, causing problems beyond "OMG I'm being attacked by a monster" to any survivors of such an attack. As the devil is wielding this weapon, it cannot be affected by its poisonous nature having "forged" the blade itself.
Any characters that attempt to wield the weapon after the monster's hopeful demise will be dismayed to see the metal literally melt away from the fixture, assuming the whole of the weapon wasn't frozen from quicksilver, Immediately they will need to make checks against the poisoning effects as the metal reaches melting points and begins to evaporate. In other words, get out of Dodge.
Poisoning effects: As a vapor, DC17 Constitution save every minute, beginning with when the "blade" reaches melting point, until the area has been cleaned of elemental mercury or the character is clear of the area. Effects are 1d4 damage to any mental ability, randomly determined, until threshold has been met of half the total of mental abilities. The save must be made every minute so long as exposure continues.
For example, a wizard with 16 Intelligence, 12 Wisdom and 11 Charisma has a threshold of 20 poisoning damage. Once the threshold is reached, one point of drain (permanent) is inflicted. The expression "mad as a hatter" can still be a thing, as you can see.
As a solid weapon, DC17 Constitution per wounding, failure means suffering 1d3 points of Constitution damage due to frostbite and mercury getting into the character's system.