Crystalline Corruption

Crystalline corruption is a curse that occurs when one continues to stay Dominated by Sileeris or a crystal of one of the Gem fiends is implanted into the target. It takes a total of 1d20 days to increase in level, which the DM rolls and keeps track of, telling the player when the time comes. It is rerolled when the player increases the level of the curse. Each Gem fiend causes a different crystalline corruption with different effects. The thing is, that many who gain this curse refuse to have it removed due to the benefits that the condition causes. This These include:
Sileeric Corruption

level	effect
1	You begin to feel the presence of Sileeris, and cannot eat normal rations. You must consume blood to gain sustenance.
2	The transformation becomes complete and cannot be reversed. Your creature type becomes Fiend and you magically know Infernal or Abyssal (whichever the DM decides Sileeris uses more). While in the progress towards the next level, your alignment slowly turns evil and your will becomes entwined with Sileeris.
3	You gain the Crystal Resistance of the Gem Fiends, but a vulnerability to thunder damage.
4	You gain resistance to non-magical piercing and slashing damage, but weakness to bludgeoning damage.
5	You gain the Dominating Will trait and Dominating Breath action.

Ceclic Corruption

level	effect
1	You begin to feel the presence of Ceclyx, and require double the amount of rations. You can also eat non-food items to gain sustenance.
2	The transformation becomes complete and cannot be reversed. Your creature type becomes Fiend and you magically know Infernal or Abyssal (whichever the DM decides Ceclyx uses more). While in the progress towards the next level, your alignment slowly turns evil and your will becomes entwined with Ceclyx.
3	You gain the Crystal Resistance of the Gem Fiends, but a vulnerability to acid damage.
4	You gain resistance to non-magical slashing and bludgeoning damage, but weakness to piercing damage.
5	You gain the Familiar Summoning and Hungry Jaws action that Ceclyx possesses.

Xipuanic Corruption

level	effect
1	You begin to feel the presence of Xipuanaeus, and you feel empty without something to learn. While reading, you gain sustenance and rejuvenate from exhaustion even while your body withers away.
2	The transformation becomes complete and cannot be reversed. Your creature type becomes Fiend and you magically know Infernal or Abyssal (whichever the DM decides Xipuanaeus uses more).
3	You gain the Crystal Resistance of the Gem Fiends, but a vulnerability to cold damage.
4	You gain resistance to psychic and force damage, but weakness to necrotic damage.
5	You gain the Sequestered Knowledge and Fractal Tentacles action that Xipuanaeus possesses.

Each of the abilities for each type of corruption are listed below:

• Crystalline Resistance. The Corrupted takes less damage from magical attacks equal to the damage divided by his CR. (M-(C/2), where M is the magical attack and C is the CR or character level).
• Dominant Will. Whenever a creature is hit by a Dominating Breath attack caused by the Sileeric Corrupted and critically fails the Constitution save, it must make an additional Wisdom saving throw (equal to your Save DC) or be dominated. Dominated acts like charmed, but as a curse and can only be removed by the spell, Remove Curse or until Sileeris grows tired of the control. When under the Dominated condition, the target can be commanded by Sileeris and his minions, such as certain Boldroths, Silmora, or any mage or intelligent minion.
• Dominating Breath. The Corrupted exhales a burst of foreboding reddish black mist in a 30-foot cone. Each creature in that area must make a Constitution saving throw (equal to Save DC), taking 11 (2d10) slashing damage on a failed save, or half as much damage on a successful one. The Corrupted then regains hit points equal to half the damage dealt by absorbing a portion of the blood spilled. Any creature that crit fails the check becomes dominated. At 5th level, this damage increases by 1d10. This increases by 1d10 additionally at 11th, 15th, and 17th levels.
• Familiar Summoning. You are what you eat. Each time you use the Hungry Jaws ability, you take a piece of the being that you devoured into you. As an action, you can summon a crystalline version of the being that is about half its original height. It possesses the same stat block as the original, but its health is halved.
• Hungry Jaws. You can throw yourself into a feeding frenzy. As a bonus action, you can make a special attack with your Bite. If the attack hits, it deals its normal damage, and you gain temporary hit points equal to your proficiency bonus. You can use this trait a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest. Your bite deals 1d6 piercing damage plus your Strength modifier; this trait increases in strength at 5th, 10th, and 15th levels, each time gaining an additional d6 in damage.
• Sequestered Knowledge. The Gem Fiend of Knowledge has found favor in you and given you access to the library he keeps. For each spell that you learn from him, you gain an additional spell slot of that spell's level. When you use that spell, you can cast a divination or illusion spell for free as a free action.
• Fractal Tentacles. As an action, you can expend your highest spell slot to summon otherworldly crystalline tentacles to aide you in battle, and appear within 15 feet of you. The amount of tentacles is determined by the level of spell slot used. Each tentacle has a range of 15 ft, deals 1d12 plus your Intelligence modifier, has the Crystalline Resistance you possess, has x health (where x is your character level), and immediately attacks at the end of your turn. They last for a duration equal to the spell slot used. This can be done a number of times equal to your proficiency bonus and regain all expended uses when you finish a long rest.

Type

Supernatural