Age of Ascension: Forging an Immortal Realm from Nothing

Day 15!
The monster invasion arrived right on schedule. The Void was "merciful" like that during the rookie trials—you got your daily dose of death and destruction, guaranteed. The familiar sounds of battle erupted, and by the time Wu Chi got to the wall, everyone was already in the thick of it. After fifteen days of constant fighting, they didn't need him to micromanage ❀ Nоvеlігht ❀ (Don’t copy, read here) anymore.
The Great Qin Vanguards weaved in and out of the tower barrages, their Qin swords and halberds reaping a bloody toll on the enemy. Up on the wall, Lin Daiyu stood with her new sword, a silent, deadly guardian. After all, you never knew what kind of boss the Void would throw at you next. They'd faced bizarre freaks, stealthy assassins, powerful mages, and disgustingly tanky behemoths. As the territory's strongest fighter, it was her job to stand guard against any nasty surprises.
"Young Master," she said with a solemn nod as Wu Chi approached.
He nodded back, his gaze shifting to the Moon Palace cultivators. They were nervous, their little faces tense, but they were methodically casting their spells. One hand would apply a [Lifeforce Seal] to a Vanguard, while the other launched a [Wrathful Moon Seal] at an enemy. Their dual-casting ability was proving to be incredibly efficient.
"They're green, but they're fast learners," Lin Daiyu commented, noticing his gaze. "They'll be fine soldiers soon enough. But," she added, "they'll never be a match for the Vanguards."
"Their combat instincts are on two completely different levels," Wu Chi agreed, unconcerned. He was more than happy with the girls' performance. "Besides, their job is to cast spells from the safety of the [Thundercloud Wall]. They don't need to be frontline killers."

"True," Sister Lin conceded.
This time, the invaders were slimy, black creatures called [Swamp Lurkers]. A horde of about a thousand, ranging from levels 12 to 15. They were reasonably strong, but their main advantage was, well, swamps. Out here on dry land, they were laughably out of their element, like fish out of water. They were basically walking target practice. The battle was a grind, but not a difficult one. The towers thundered, and his two squads were slowly but surely developing a good rhythm together.
"Looks like we got lucky today," Wu Chi said with a smile.
Lin Daiyu remained silent, her eyes scanning the horizon. Her thousand-plus attribute points gave her superhuman senses, allowing her to anticipate danger before it struck.
The fighting dragged on into the evening. The swamp monsters came in waves, a relentless, attritional assault. Thanks to his troops' high stats, exhaustion wasn't a major issue, but just to be safe, Wu Chi had them supplied with "Moon Essence Liquid" from the [Moon Wells]. The Vanguards drank it without a word, while the cultivators offered sweet thanks, their tense faces finally relaxing into smiles.
…
7 PM!
After wiping out another wave of several hundred monsters, Wu Chi surveyed the trashed battlefield and began restocking his towers.
"Young Master! Time to eat!" Qin Keqing arrived with a food basket.
Wu Chi took it and began laying out the food. "What about the others?"
"Sister Daiyu has already delivered their meals," she said with a gentle smile. "Are you… training them, Young Master?"
"I am," he confirmed between bites. "And it looks like they're going to be fine."
"Yes, they're improving very quickly," Qin Keqing agreed, a serene look on her face.
He was halfway through his meal when…
SCREEEEEE—!
A piercing shriek ripped through the sky, so sharp it was a physical force. Everyone flinched. Wu Chi looked up. A massive, rotting bird had appeared above the mist, its feathers matted and decayed, black fire burning in its eye sockets.
"Boss!"
He slapped on his [Lens of Truth]. Yup. The Day 15 boss: a Level 15 [Rotting Swamp Great-Raven].
"First flying boss, huh?" Wu Chi muttered, his eyes glued to the sky.
The towers opened fire. Control effects shot upwards, but… it was kind of awkward. Most of his crowd control towers, like the [Earth Vine Tower], were useless against flying targets. The only one that had any effect was the [Fart Tower].
The Great-Raven took a big whiff of the noxious gas. It let out a choked, agonized squawk and nearly fell out of the sky.