Isaac opened his eyes and happiness glinted within his icy pupils. He stood up and spent a minute stretching his stiff limbs, then he went to his cupboard and grabbed a large amount of food. Suddenly, he stopped himself.
'Right, I still need to cultivate later so I can't eat now. I didn't eat breakfast either, so I'll need to eat a huge dinner... I'm famished right now. Actually, what time is it? If it's already night-time, I might as well eat since there's no time to cultivate.'
Isaac put the food back into the cupboards and walked over to the window. When he opened it, he could see the sun setting in the west; it must've been about 1pm. Since there was plenty of time left to cultivate, Isaac could only sigh and give up on eating lunch.
He closed the window and sat back down on the mattress, but he didn't start cultivating immediately. Instead, he considered the benefits of reaching middle stage and what he should do next.
'My Qi Core's empty right now, so I'll have to wait for it to fill naturally. When it does fill up, my Qi will be purer and slightly more powerful, so any Anima I use will experience a minor boost in strength.'
If an Anima was like an engine, Qi was its fuel. Using Rank 1 lower stage fuel was like trying to power your engine with vegetable oil: it might work, but the fuel would be hard to burn, and produce a sub-optimal result. Then, Rank 1 middle stage would be like a better brand of oil. It might burn a bit more smoothly and produce a slightly better effect, but it wouldn't be too different. Upper stage would be like using even better oil, and then Rank 2 would be like using a different fuel entirely: stages were small improvements, while a rank was a huge leap in quality.
When Isaac advanced, he'd refined each of his main 12 meridian points using 3 blue crystals. They would still automatically absorb atmospheric Qi to fill Isaac's Qi Core, but now the process was different. It hadn't got any quicker – in fact, it had become slightly slower. However, his meridians could now filter Qi to make it slightly purer. That meant his Qi Core would always fill up with middle stage Qi instead of lower stage Qi.
The process of meditation would also change now. Going back to the example of fuel, atmospheric Qi was like the lowest quality vegetable oil that you'd use at lower stage. Middle stage cultivators like Isaac could absorb it, but they usually wouldn't.
It would be much more beneficial to strengthen the walls of their Qi Core with purer middle stage Qi. That would give them a stronger foundation and increase their chances of future breakthroughs.
Since directly absorbing ambient Qi was a no-go, an extra step was needed. Isaac had to take a moment to filter Qi when he brought it through one of his meridian points. However, that filtering process meant Isaac's cultivation would be slightly slower than before. Absorbing pills was the same; Isaac would have to channel the pill's Qi through his stomach meridian and filter it before he absorbed it.
Despite these complications, the overall strength of a middle stage cultivator was significantly better than a lower stage one. This was partly because of the boost to their Anima's power, but it was also for another very important reason: they could own more Anima.
Just like all creatures, Anima needed food, and their food was Qi. Normally, Anima would live in places with high ambient Qi so they always had enough for sustenance, but that changed once somebody refined the Anima and came to own it. They would bring it to all different kinds of places, many of which would not have enough Qi to feed the Anima. This was why, after being refined, Anima needed to dwell in a cultivator's body: the cultivator could supply them a small but constant stream of Qi.
This stream was comparatively large for some Anima and small for others, but whatever its size, it never exceeded the cultivator's natural rate of recovery. The amount of Qi an Anima consumed per second under normal circumstances was referred to as its 'idle consumption'.
Rank 1 lower stage cultivators had a high natural rate of recovery, but their Qi was impure and they could only support the idle consumption of 2-3 Anima depending on their consumptions. Of course, this was also considering that total idle consumption had to be slightly lower than natural recovery rate, otherwise the cultivator would never be able to recover their Qi (unless they wasted resources to do so).
Compared to a lower stage cultivator, a middle stage's natural recovery was slightly slower but their Qi was purer, so it could support the idle consumption of 3-5 Anima. Then, an upper stage cultivator could own 4-7 Anima of their own rank depending on which Anima they chose. Of course, there were some Anima with extremely low (or no) idle consumption, and some with excessively high consumption, but those were exceedingly rare and could only be considered exceptions to the rule.
For Isaac, his Spirit Sword Anima had a rather low idle consumption while the Snowshoe Anima's was above average. Even if he was still lower stage, he could've got another Anima, but it would've reduced his natural recovery to a snail's pace. Now that he was at middle stage, he could comfortably fit more Anima. This would widen the repertoire of things he could do and infinitely increase his possibilities in battle. But that was if he could afford one... which he definitely couldn't.
This meant he'd broken through to middle stage but couldn't take advantage of its greatest benefit. He had a lot of things on his plate right now: finish secluded cultivation, create a team, catch the eye of a good faction, prepare for the newcomers' tournament which was inching ever closer, and find a way to try and increase his talent. Now, acquiring his 3rd and possibly 4th Anima had joined that list.
However, what was in front of him right now took priority. He still had 10 Basic Qi Pills, 9 days left in the room after today, and many hours to continue cultivating now.
Isaac picked up one of the pills in front of him, popped it into his mouth and entered meditation.
*************************
9 days passed like a flash. Well, not for Isaac it didn't. It was over a week of continuous effort and cultivation for him; I mean it passed like a flash for you.
Isaac had already finished cultivating. He was packing up the remaining food he hadn't eaten and getting ready to leave.
It had been a successful period of seclusion: he'd broken through to middle stage, then used those last 10 Basic Qi Pills to strengthen his Qi Core until it could be 42.9% full. To put that in perspective, he'd used 10 Basic Qi Pills and progressed from 33.3% to 42.9%, an improvement of 9.6%. When Isaac had gone into seclusion the first time, he'd progressed by 13.3% with every 10 Basic Qi Pills: it was already clear how much slower cultivation was in middle stage.
However, that was the law of cultivation: the higher you got, the harder it became. Isaac already knew this, so it didn't discourage him one bit. In fact, he was only motivated to keep pushing through the difficulty and hardships: he thrived on adversity – for what others would deem difficult, he would only see as a challenge.
He packed his things, content with the step he'd taken in his cultivation journey. Then he headed home with his near-empty bag of food, walking under the moonlight. He was bathed in light, as if the moon was calling him, but he quickly shrugged off that feeling.
The moon didn't need to call him – he would find a way to soar through those boundless skies by himself.