A/N: Enter Aizen.
4: Kido
"Ye lord! Mask of blood and flesh, all creation, flutter of wings, ye who bears the name of Man! Inferno and pandemonium, the sea barrier surges, march on to the south! Hado number 31, Shakkaho!" A red ball of energy shot out from Sakura's palm, blasting a hole through a pile of sandbags set up against the wall. Walking over, she checked the damage. The hole went straight through the triple-layered sandbags, singeing the wall behind them. "Whoops," Sakura muttered to herself, quickly grabbing a sandbag and covering up the scorch marks. Returning to a spot about ten feet away from the wall, she pointed her finger at the sandbags again. "Hado number 54, Haien!" One of the sandbags disintegrated, leaving a pile of sand and scorched canvas.
Quiet applause sounded from behind her. "Very nice job, Kuchiki-san. A fiftieth level Hado without the incantation is quite impressive for someone of your age. I see that Kuchiki-taichou wasn't joking when he said your Kido skills were formidable."
Sakura jumped and turned around, finding herself faced with chocolate-brown eyes behind square-rimmed glasses. This was Sousuke Aizen, lieutenant of the fifth division, she realized. "Ah, hello, Aizen-fukutaichou! I didn't know you were coming today; you scared me."
The chestnut-haired lieutenant laughed, a rich, warm sound. "My deepest apologies. That was not my intention. My curiosity got the better of me, I'm afraid." He took a few steps closer to the noble girl, carefully avoiding the scraps of burnt canvas and sand. "May I ask how far your Kido knowledge goes, seeing as I will be training you from now on?"
Sakura paused. "Um, I've learned about all of the Bakudo spells, as well as all the Hado spells up to 90."
"Oh?" Sousuke looked surprised. "That is most impressive. Can you perform all of those?"
She shrugged. "Not really. Up to 60, maybe. Anything higher than that is weak, so…"
He smiled. "So we'll work on those, is that all right?"
Sakura nodded. "Sure, Sensei."
"All right," the chestnut-haired lieutenant said, pushing his glasses up on the bridge of his nose, an action Sakura found rather endearing. "Now, let's try a Bakudo spell first, shall we?"