The Demon Sword Asperides, by Sarah Jean Horwitz

 "If it was possible to somehow glow mockingly, Nack was pretty sure Asperides was doing it."

Oh goodness, I enjoyed The Demon Sword Asperides, by Sarah Jean Horwitz (July 2023, Algonquin Young Readers) so much!!!!  And basically, just want to say this repeatedly instead of writing something review-like.  But here we are...

So Asperides is a demon sword, quietly nursing a drink in his* favorite underworld pub (not actually drinking, because of being a sword, but peadefully contemplating) as is his habit--it's been years and years since he was wielded in battle, and being a demonic pub regular is at least something to do.  Up in the human world, he is pinning down his last master, Amyral Venir, a horror of a being who is not only stuck in place by his own ex-sword but sealed in a tomb warded by various curses, ferocious magical beings, etc.  

Nack is the younger son of one of a bunch of feuding clans, who has just failed "knight in training" rather badly, so much so that his family has disowned him.  He is desperate to find a quest to complete, to prove his worth to them, and hopefully be found worthy of an angel blade (literally angel infused) such as is wielded by the very best paladin-like knights.

The lost third moon is also an important player here--it's coming back, which means the weakening of the shields between the demonic and the human worlds.  And this means that the wards of Amyral's tomb are failing, and the watch beasts are getting out and menacing people.

Nack leaps on the opportunity to quest against the marauding watch beasts and ends up inside the tomb.  Asperides, stuck there, can't help but be the demonic sword he was forged to be.  He presents himself as an angel blade to Nack, points out that the two very nice married (to each other) woman paladins who also came to the tomb are about to be slaughtered, and glosses over the bit of the contract where Nack's soul will belong to Asperides for eternity.  Nack bites, and is rather thrilled with his new "angel" sword, even though he's taken aback by its rather salty, un-angelic, communications.  And off they go to fight for truth and justice (a change for Asperides, but one he thinks he could get used to...)

But then it becomes clear that Nack and Asperides have to save the world from the resurgence of Amyral Venir.  Even a demon sword isn't enough to make Nack a hero capable of saving the day alone so lots of story happens with other great characters and some icky undead birds etc. and it is great.

The snarky demon sword with a redemption arc is wonderful, and the wounded young teenager kicked out of his family finding the strength of will to recognize he doesn't actually need their approval is also excellent.

The pacing is brisk, the other characters are great, and the plot is pretty darn good too.  And it made me laugh.  It is marketed as middle grade (9-12 years old), and is great for that age range, but it has enough zest to make it appeal to older readers as well.  I am, in fact, pretty sure I am about to make a convincing argument to myself that I need to go out and buy a copy for myself (because what is the point of being a grown up if you can't go buy books?)

nb--The Demon Sword Asperides is eligible for the Cybils Awards this year, so keep it in mind when the public nomination period opens Oct 1!

Note on the sub-genre of sentient swords--I can only think of two other sentient swords (swords that possess their wielders with berserkery bloodlust don't count)

Have Sword, Will Travel, by Garth Nix and Sean Williams (mg, my review)

Swordheart, by T. Kingfisher

and I was just reminded of a third most excellent sword, in Nightingale, by Deva Fagan (mg, my review) 

This is a relatively small niche, but a good one.  Every sentient sword I've met so far has been a pleasure, so please add to my list!

*pronouns are discussed, because the characters aren't sure which to use for the sword.  "He" is deemed an acceptable choice.