The pills in the lower tier are not that different from each other not is there much importance attached to them but the pills of high tier are different.
Especially so for those that have reached the Spirit refining stage. This kind of pills are further divided into 5 grades depending on various factors such as the toxicity, it's effects and it's usage.
The order starts with the pills that have accomplished the 20% conversion rate, meaning that the pill contains 80% poison in it. This kind of pills are known as low tier pills.
The next is the pill that has accomplished the 35% completion rate and contains 65% poison in it. These level of pills are known as mid-tier pills.
Then comes the high tier pills that have accomplished the 70% completion rate and such the pill contains only 30% poison.
The fourth rank pills are the one that have pills which have accomplished 90% of the completion rate and contain a minimal amount of 10% poison. This pills at know as the peak tier pills.
And the last and the highest quality pill which is even considered legendary as even in the books that he had read had only mentioned that they had found such pills by chance from ancient ruins.
These pills at known as the perfect pills as they do not contain any poison in them and are at 100% completion rate.
These pills are said to have such a high concentration of spirit energy in them that sometimes the pill might come alive and form a body for itself if given enough time.
As you can see all these pills have different levels of benefits but that is not that important if you are just going to use them for normal cultivation practice.
But when it comes to the point of breaking through any realm or stage it is very important that the pill that you use is at the fair minimum at least of high tier.
This is because when you try to breakthrough your spirit energy in your body is in a very volatile state which leads to the current predicament of the pill usage.
If you use a low tier or a mid-tier pill when you breakthrough than it causes a problem because of this volatility.
As you try to break through your spirit energy try's to break the wall that is blocking its way ahead the energy of the pill acts as an extra helper in this push.
At such a time your spirit energy can be considered as a mad man who will use anything to break that door whether it be a similar kind of man or spirit energy or a person who will cause him harm such as the poison in the pill.
As such as not to cause the inflow of poison within your spirit channels it is best to use high tier pills.
Finally, the third method of breaking through from the shackled realm is to have the help of a cultivator of at least 3 realms above you help during the breakthrough to not only break your shackle but to also help build your foundation.
This method not only has a higher success rate but the foundation built-in such a way in your dantain is much more stable than the first method itself.
But using these methods has various problems in itself. The first and foremost most is finding a cultivator of the 4th realm is easier said than done.
Second even if one finds such a cultivator and even if the cultivator agrees there is the problem of whether you yourself will trust him, since he can make you strong he can take some measures and plant something in your foundation so that when he wants he can cause you problems.