Call the Blood

The more you have, the more you crave.

Call the Blood is a powerful Blood spell that lets the mage glut themselves on suffering and bloodshed all around them. Every drop of blood spilled on the battlefield draws towards the mage, providing them with both raw magical power and fuel for other Blood spells. A dreadful and potent spell, it requires the sacrifice of one suitable life to be cast.

Effect

Call the Blood causes all bloodshed within a wide area to flow towards the mage by its own accord. The spell snatches blood from hundreds of meters away, drifting towards the mage as soon as another wound is opened. It functions best on a large battlefield, where the melee's constant swirl provides a deluge of pain and blood. The blood moves quick as a viper, and across a large field it can take time for every stream to reach to mage - greedy Blood Mages place themselves where the fighting is fiercest to chase the blood. More prudent spellcasters allow the trickle to come to them, keeping themselves away from the action instead of adding their own blood to that spilled.

The Call of Blood is indiscriminate, and mages must be careful, lest they are forced to imbibe blood poisonous or otherwise hazardous.

Once it reaches the caster, the blood surges into their body, puncturing veins or snaking down the throat to get in. This blood can be used by the caster as fuel to cast other Blood spells, just as that of a sacrifice would, at a reduced rate. In addition, the infusion empowers the mage, increasing the potency of any Blood spell they do cast. This potency drains just as the blood does, making it ebb and flow as the battle around the mage does. As the blood flows into the wizard, they begin to bloat from the excess fluid, puffing up with every siphon of blood. Any scratch or cut bleeds (or if enough blood has been consumed, gushes) from the mage and movement becomes slow.

Some mages become so nauseated that they begin to burn their excess blood with any spell they can cast, turning into terrors for both friend and foe.

Mages who cast the Call must strike a balance between the power it offers and its dangers. At least one spellcaster became so bloated on stolen blood that they finally popped, like an overfed tick hit with a hammer.

Power

Greater

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Undead Mages

Undead users of the Call of Blood often have to prepare - a skeletal lich will find the gore gush out from their less-than-waterproof body. Ethereal undead must as a variant of the spell that uses both Necrotic and Astral magic to transmute the blood to a substance they can use - and most don't bother.
Vampires are especially dangerous users of the Call of Blood, as they have many more uses for the blood than just magic.

by Rock Cafe.info

In the World

With the Call of Blood, a Blood Mage can bypass (or at least limit) the requirement of sacrifice to fuel their more powerful spells. On a busy battlefield, they are only limited by the rate at which blood reaches them and the intensity of the fight. Even then, the spell is unpleasant and dangerous, with even the most hardened blood mage squirm at the idea of blood forcing its way into their flesh to swell their veins. The spell itself is not the only danger - that flailing, writhing tendrils of blood rushing through the air and towards the spellcaster all but announces them as a dangerous foe to target. Even worse, as they bloat, they become all the more easy to hit.

It is a rare spell to find, and masters of blood don't tend to share their secrets. Learning Call the Blood is another challenge that limits its use on a wider scale, at least for now.

Though the most famous depiction of the Call of Blood is that of a battlefield scourge, it has more subtle uses. Some Blood mages use it as part of a ritual, where a steady stream serves their purpose better than one gruesome orgy of bloodletting sacrifice. Others, particularly danger mages, come to enjoy the sensation of stolen blood coursing through their veins.