Malum

Malum adds a couple new things to spice up your worldgen.

The Runewood Tree is the most notable addition to world generation. 
It's a huge tree that spawns in forests and more commonly, plains. The ground around the tree will be altered, providing you with lavender; a new flower. The leaves of the tree appear in a gradient. 
Rarely when you strip runewood logs you may find solar sap. This rejuvenating substance can be used to produce sapballs and can be heated up into solar syrup.
Wood from this tree will be one of the two things you need to start your magic experience.

Soulstone is a new ore that generates within the overworld, similar to coal. It spawns more and more commonly the lower you explore. 
This arcane gem will be the second item you need to become a proper warlock.

 
Blazing Quartz is another new ore, it's found in the nether.
It makes for a fine furnace fuel, and has a couple uses in magic.

– The Runewood Tree:

– A Soulstone Vein:

– A Blazing Quartz Vein found next to regular quartz:

Like previously stated, Malum is centered around spirits. When you kill a living being, you destroy it's body. Harvesting spirits requires you to go a step further, not only slay their body but also shatter their soul.

Spirit Harvesting is the first step into magic you will take.
Each entity contains it's own unique set of spirits, of which there are many types.
The most primitive means of harvesting spirits requires a crude scythe, a novice warlock's tool. Final blows with a scythe will succesfully shatter your opponent's soul, resulting in spirits.
Scythes aren't just a tool though, they're a proper weapon. They're slow weapons with enhanced sweeping capabilities. 
They also come with their own enchantments, rebound for example allows you to throw your scythe like a boomerang.

Spirit Infusion is a process that takes place at the Spirit Altar, an arcane workbench of sorts. 
Spirit Infusion requires a prime item placed directly on the altar, a set of spirits surrounding the prime item and any additional items an infusion recipe may require. 
Additional items must be placed on item pedestals or stands, which can be made from most building blocks within Malum.

– A successful Spirit Harvest:

– Tainted Rock Spirit Infusion:

– Tainted Rock Arcana Entry:

– Ether Spirit Infusion:

– Ether Arcana Entry

There are a ton of things Malum adds, and many many more to come. Here's some of them!