Dream Mirror has unique concept of playing with tagging out to their counterpart using "mirror" field spell. It also has great artwork like Trickstar but combined with Darklord.
The play is very simple, we need
Dream Mirror of Joy + Ikelos, the Dream Mirror Mara. To accomplish that we use 3 Mara, 3 Joy, 3 Phantasms (allows more interruption by searching Morpheus), 3 Diviner (send and use Trias to ss Mara), One for One, Terraforming, and Set Rotation (makes us unable to switch the field spell tho). Use Mara ss Sprite, use Sprite add Dream Mirror of Chaos/Morpheus/Oneiromancy (if we use Set Rotation, we will stuck on Joy field, means only Oneiromancy can provide interruption). At the end phase, switch the field to Terror so Chaos/Morpheus is online (Sprite can ss Mara to summon Morpheus from hand).
While we have 3 interruptions to choose, they all have their own downside. Morpheus: Best one imo, destroy card, big body, but difficult to work if you activate Set Rotation. Oneiromancy: Versatile, still online even with Set Rotation, but doesnt have body. Fusion: Biggest body, negation can be used again next turn, but doesn't destroy and doesn't work with Set Rotation.
The ratio is explainable, starters are 3 ofs, irreplaceable combo pieces as 2 ofs, and the searchables as 1 ofs. The rest of the deck is just good staples while being monster so One for One has higher chance to work.
Pros: Fun and unique gameplay, big staple slot.
Cons: Weak and struggle in grind game.