Marvel Universe

You have invented a device capable of locating the Infinity Stones scattered across the entirety of the marvel universe. You have your own ship you built for intergalactic travel. Your research has told you that each Infinity Stone is guarded by a very powerful being (whose identity will be revealed upon arriving to location) that you must defeat to get to the stone. If you defeat the guard, you must then answer a very difficult riddle in order to break the very powerful protection spell on the box containing the stone.
INFINITY STONES:
Power Stone – Powered by the user's mastery of mind. Increases strength and durability, enhances virtually any known superhuman ability, energy manipulation. It also supplies the other gems with their power/energies.
The Power Stone has the power to destroy any living material to come into contact with it, and emits a violet light.
Space Stone – Powered by the user's mastery of power. Allows travel through space, mostly through teleportation. Able to interfere with the motion of other objects.
The Space Stone is able to generate an infinite amount of energy and generate portals to other locations and gives off a blue light. Residing in a cube known as the Tesseract.
Time Stone – Powered by the user's mastery of space. Allows for time travel; stop, slow down or speed up flow of time; accelerate or slow down ageing; see into the past and future; and bend time to the user’s will.
The Time Stone, which emits a green light, allows its user to manipulate time.
Reality Stone – Powered by the user's mastery of time. Alters all of reality; similar to the effects of a Cosmic Cube, but much, much higher.
The Reality Stone is capable of warping reality to the user's desires.
Soul Stone – Powered by the user's mastery of reality. Observe, attack or even steal a being's soul or spirit. Also used to revert individuals to their natural state.
The Soul Stone has the ability to manipulate life and death.

Mind Stone – Powered by the user's mastery of soul. Near-limitless psionic/psychic abilities including empathy, telepathy, and telekinesis.
The Mind Stone has a variety of powers related to the mind.
The Ego Stone In a primordial era of Earth-616, a god being with the power of Infinity committed suicide out of loneliness and its aspects split into seven Infinity Gems that could grant portions of that power to whoever held them. One of the Gems was lost to a different reality, Earth-93060, also known as the Ultraverse. While the other six carried aspects of the being's influence over external reality, this seventh Gem carried the vestiges of the being's psyche. The Ego Gem's consciousness was able to partially possess beings that came into contact with it. Though they retained much of their free will, hosts were compelled to act in the Gem's interests. When joined with the other Infinity Gems, it formed the core consciousness of a cosmic being formed from their union. the Ego Gem could merge with the soul, space, time, mind, reality, and power stones incarnated into a being called Nemesis.
The Chaos Stone gives the user the ability to hold the power as well as wield and gain control over Chaos energy.