In Ovid's Metamorphoses, Ikelos (called Phobetor by the gods), Morpheus, and Phantasos are somnia, children of the personification of sleep Somnus. Ikelos appeared in the dreams of mortals in the form of a beast, while Morpheus appeared in the form of a human, and Phantasos appeared in the form of inanimate objects.
The "Dream Mirror" playstyle utilizes a duo of Field Spell Cards, "Dream Mirror of Joy" and "Dream Mirror of Terror", in order to switch between the defensive LIGHT Attribute versions of their Main Deck monsters and the offensive DARK Attribute versions, who activate their individual effects when Special Summoned by the effect of a "Dream Mirror" monster. Joy and Terror each have an End Phase effect to cycle to their opposite that works in tangent with "Dream Mirror Fantasy", but you will more often use "Dream Mirror Hypnagogia" to place both Field Spells on the board as a means of using both series of effects. In this state, "Dream Mirror" are capable of solid field presence and disruption and are able to set up their plays by swapping into their opposites depending on the situation; such as using "Morpheus, the Dream Mirror Black Knight" for disruption and "Morpheus, the Dream Mirror White Knight" afterwards to protect the lower level "Dream Mirror" monsters from attack. Combine this with "Dream Mirror Recap" and you can loop the Main Deck monsters more effectively.
Because of the Deck's focus on LIGHT and DARK monsters, various "Chaos" monsters can be teched in to help propel their playstyle further. The ones of note especially are "The Chaos Creator" and "Chaos Daedalus" as "Creator" allows for recovery in this Banish playstyle and "Daedalus" can banish up to two cards if both Field Spells are on the field.
What holds the Deck back however is the number of factors at play that can impact how effective their board is. Primarily, getting the wrong combination of "Dream Mirror" monsters and Field Spells in your hand, as well as lacking a means of maintaining both Field Spells at all times, can result in the Deck being unable to make a board. As such, it is recommended to use "Trap Trick" as a means of getting to "Hypnogogia" quickly and using "Field Barrier" as a means of ensuring your Field Spells are not affected by removal or other Decks with Field Spells. Certain cards in the Deck as well, particularly their Fusion Spell, "Dream Mirror of Chaos", and Counter Trap, "Dream Mirror Oneiromancy", are affected by which Field Spell(s) are on the field when you use them. so it is important to take this into account when making a "Dream Mirror" Deck. Finally, the Deck runs into the issue of running out of resources quickly due to the swapping effect Summoning from the Deck, which is only mitigated by the effect of "Phantasos, the Dream Mirror Friend". Because of this, cards that can recycle from the GY, like "Pot of Avarice" and "Jar of Avarice", are highly recommended.