This ancient jewel, powered by Cyttorak, the ruler of the crimson cosmos, binds to the user's soul and transforms them into the unstoppable Juggernaut.
The incredible energies of the Gem will cause you to transform into Cyttorak's Exemplar, the Juggernaut, a nearly unstoppable force of nature. The Juggernaut possesses near-limitless strength, stamina, and durability, granting very high levels of invulnerability. This allows you to go toe to toe with a moderately angry World War Hulk or the Mighty Thor and actually fight to a draw with a possibility of winning.
As the Juggernaut, you are completely self-sustained, having no need to breathe, eat, drink, or sleep, as well as immunity to contaminants of any kind. The self-generating mystical energies provided by the Gem cover all your needs, making you self-sustaining.
You are covered with a personal force-field that greatly enhances all your physical abilities, such as strength and durability. The field is strong enough to withstand an attack like Thor's god-blast, Adamantium weapons, or even being in the true presence of Oblivion himself, leaving you completely unscathed. This field can also be used to absorb and redirect energy-based attacks. With enough power, you can even use this field to levitate and fly. Should your force field and immense durability not be enough and you are damaged, you also have a regenerative healing factor that enables you to completely regenerate with superhuman speed from wounds on the level of being completely flayed down to a skeleton.
You are also able to change your size from being a normal human to being 80ft tall.
The greatest power bestowed by the Gem that truly makes you THE JUGGERNAUT is that it turns you into an embodiment of an unstoppable force. Once you begin to advance in a certain direction, it is virtually impossible to halt your movement unless you yourself want to. It is possible to slow you down, but unless it's an attack on the level of Thor's use of his god-blast, you cannot be stopped.
A side effect of all this is that you also gain immortality from all "natural" means that are not great enough to overpower the power of the Crimson Cosmos.
The single weak spot is the Juggernaut's mind, but you are equipped with a suit of armor that is just as durable as you are and shields you against virtually all psychic attacks. Be aware that if you are not careful, your enemies may be able to remove your helmet (though this is not an easy feat).
Note that this is only what the Gem does if you are a normal human upon bonding with it. The effects of the Gem will be much greater with a higher Baseline.