This being an extra episode and all, I had no idea what to expect, so it was a nice surprise to get a story about one of Shizu’s exploits, which takes place before Rimuru even appears in this world. As she arrives at Filtwood Castle to join a host of other adventurers in an effort to defeat a recently summoned demon, it’s made clear Shizue Izawa is already a legend among her peers and in Filtwood’s court.
But she’s weary that even the formidable Silver Wings have recently fallen to the demon, suggesting it at least has a name that lends it more power (as we’ll witness later with Rimuru’s namings). It’s also odd that the less bold adventurers aren’t allowed to leave when they hear of the strength of their foe.
After one of them is killed and a lesser demon extracted, it’s revealed they’ve all been gathered there because more of them are suspected of being possessed by demons, so they’ll all be rooted out for the good of the kingdom.
Their execution of this plan is interrupted by a cloaked mage, whose immense power Shizu only then detects (suggesting it’s an extremely powerful mage who can mask such power). The mage is himself a demon calling himself “Kuro”, and is willing to kill everyone in the hall to find the demon he’s after.
Needless to say, Shizu isn’t about to let that happen, and so…they fight.
And what a splendid fight it is! At least as good as anything TenSura has served up. Shizu is a tough customer, but even she seems to be aware that Kuro is merely toying with her, and actually holding back quite a bit. Even her special finishing move only causes as slight amount of discomfort, yet even that is the most pain Kuro’s had the pleasure of feeling in some time.
What ultimately forces Kuro to withdraw, at least for the moment, is when he gets serious and attempts to behead Shizu. Her mask protects her and relieves Kuro of his arm, making him exclaim that the mask “surpasses time.” The assembled adventurers cheer for Shizu when Kuro departs in a black cloud…but this is only the beginning of the already exhausted Shizu’s busy day.
A knight comes to her quarters to escort her to an audience with the king, and while en route, this knight expresses both his gratitude for her heroism and awe at said heroism’s form…only the ever-observant Shizu doesn’t recognize him as someone who was present for her fight. Turns out she’s right.
The “knight” is actually the real king of Filtwood, and a demon at that. Not just any run-of-the-mill demon, either: a “legendary-class Greater Demon General,” which I assume is a real thing and not something he made up in a sudden chuuni fit. His name is Orthos, and he is revered by the people as a demon-defeating hero, giving him more strength.
Orthos thanks Shizu for being a “sacrifice”, something she has no intention of doing (and also obviously won’t die as Rimuru meets her much later). That said, Orthos is a tough customer, and Shizu has had no time to replenish her strength, magic, or stamina, which is of course Orthos’ plan all along.
Unfortunately for him, Kuro reappears in the nick of time to save Shizu. Before she was summoned into this situation, she recalled what Leon told her about demon “Progenitors” who are named after colors. Kuro is one of them, an identifies Orthos as an underling of another Progenitor, Red. That means Orthos is absolutely no match for Kuro, who utterly ends him.
In the end, Kuro is credited with killing the public king and minister of Filtwood (who were really Orthos’ puppet) while official records credit Shizu with defeating Kuro. In reality, the two agree to go their separate ways and forget they ever saw each other, and in exchange, Kuro won’t end Shizu like he ended Orthos. Still, Shizu predicts “someone will do something about that demon someday”…and that someone turns out to be Shizu, summoning him as “Diablo.”
This extra episode took a while to get going what with the need to set up an entirely new setting and scenario, but once Shizu drew her sword, good things started happening. It was a fun, exciting outing that added texture to the vast world of TenSura, not to mention demonstrated that it can do just fine without Rimuru or any of his entourage.