With the Altar upgraded to Tier 4 you will now be able to craft Demonic Slates, these are crafted by placing a Imbued Slate into the Altar with at least 15,000 LP. Remember that not having enough LP in the Altar will still drain the LP but will not complete the craft until you give it more LP.
With the Demonic Slate you will be able to craft 3 New Runes for your Blood Altar:
Unlike most runes, the Rune of Acceleration works best only when paired with other runes, and its effects only increase to a limited amount. What this rune does is it increases the number of processing ticks that can occur in a given period of time, specifically when it comes to the Displacement Rune and Charging Rune. For each rune added, the number of ticks before the next processing tick decreases by one. For instance, by default the Displacement Rune displaces liquids at a rate of one operation per 20 ticks - with 10 Runes of Acceleration, this would occur at a rate of one operation per 10 ticks. Obviously the maximum number of Acceleration Runes that presently matter is 19 - if you have this many, the Displacement Rune and Charging Rune will both activate their effects each tick.
The Rune of Augmented Capacity functions similar to the Rune of Capacity in the sense that it increases the capacity of both the main tank and the I/O tank of the Blood Altar, so each time you add one of these Runes to your Altar, you will see 1% of the new total capacity of your main tank drained by the I/O tank. Of course, this phenomenon is impacted by the Displacement Runes. However, multiple runes on the same altar will begin to resonate with each other, increasing the capacity exponentially the more there are. One rune by itself will apply a +10% increase to the capacity of the altar, however this functions multiplicatively with other Runes of Augmented Capacity: if there are two runes, it is a +21% increase, three runes is +33.1% increase, etc. Unfortunately, this multiplicative effect does not stack with the Rune of Capacity, meaning you will still only get the +2kLP bonus per rune.
The Charging Rune is one of those beauties that will completely change the operation of the Blood Altar to something that can be seen as more useful for one-stop crafting. By syphoning off the LP from the Blood Altar slowly, the Charging rune begins storing "Charge," an internal value of the Blood Altar that can be seen using the Seer’s Sigil. If the Blood Altar has enough Charge when it gets something to craft, it will use the required Charge up immediately and craft the item instantaneously. If there is not enough Charge, the Charge is all used to increase the progress of the item at a 1:1 Charge:LP ratio. The maximum amount of Charge that can be stored in the Blood Altar is a function of the number of Charging Runes that it has multiplied by the current capacity of the altar, but the capacity of the altar only comes into effect if it is greater than 20k: below, each Charging Rune can stock 1000 Charge while above, each one contains an amount of Charge equals to 5% of the LP capacity of the Blood Altar. Without Acceleration Runes, it will convert LP into Charge once every 20 ticks (one second). So if you were to design a Blood Altar with this rune, careful consideration will have to be made for all of the synergistic relationships that it has.
In this Tier, after obtaining your Master Blood Orb, you will be able to craft the Rune of the Orb, which increases by 2% additively the maximum capacity of your Blood Orb. It doesn’t seem much in the low Tiers, but with the Archmage Blood Orb (Tier 5), each Rune of the Orb placed on your Altar will give you a bonus of 200,000 LP.