Basically, this card lets you destroy any monster on the field in battle by making it 100 points stronger than the monster its battling. If the opponent's monster is in ATK position and has a higher DEF, it will inflict more than 100 damage but this is an extremely rare and insignificant case.  
 
Redolent of cards like Axe of Despair and Malevolent Nuzzler is the effect of returning it to the deck (top: if you want to draw it next turn & bottom: if you want to draw it eventually) by paying 500 life points.  But that is also minutia because returning it to the deck doesn't grant it any sort of card advantage potential.  That, and it's not really a good card, so you wouldn't want to draw it again.
 
So, the pros.  It lets your monster get over anything.  It's also slightly reactive since it's a deterrent for your opponent's monster attacking.  Maybe this card would work for a monster that is protected from card effects but needs protection from attacks.
 
The downside, MMS is an equip card and suffers the same downsides as most equip cards.  If the monster is destroyed by a card effect, you lose the equip spell.  Minus one.  If the equip spell is destroyed, your monster is vulnerable.  If you're low on monsters MMS is a dead draw.  Archetype decks are better off using archetype support than a generic equip.  Deck space is tight and this card isn't really imperative.  
 
Might be okay in the most casual of duels (probably good in a draft tournament).  It's not a horrible card, but it's still leans on the side of bad.  Had it been released like 12 years ago in Magic Ruler, it probably could've been an Ultra Rare and maybe a staple in the beatdown format.  But nowadays, the game is just more complex (there's more to YGO than just having higher ATK points ; removal is easier to access than ever).
 
1.75/5

Having the day off for Memorial Day yesterday, we open our week with Moon Mirror Shield.  Honestly, as far as Equip Magic cards go, this thing isn't bad.  It gives the equipped Monster attack and defense equal to the attack or defense of the Monster it attacks (whichever is higher) plus 100 during Damage Calculation.  Also for a plus, this works during Battle, ie whether your attacking, or being attacked.  The problem being...it's an Equip.  Why even bother to destroy the Monster when your opponent can simply destroy this, then destroy this card as a result through Battle?  You're also allowed to pay 500 Lifepoints when this card is sent face-up from the Field to the Graveyard to return it to the bottom of your Deck. That's a rather lackluster effect.  If Equips were better, or this card were better, it might be worth playing, but it's just not.
 
Rating:  2/5 
Art:  4/5

Hello Pojo Fans,
 
Moon Mirror Shield is an equip card that can be very annoying to your opponent if played correctly. Pump up any monster you have equipped with this card to match the opponents ATK or  DEF, then you get the +100 point boost to make sure its stronger. While this is very good, and it reminds me of Cat's Ear Tribe, there are a few downsides to this card.
 
One, it's an equip spell, so it is very vulnerable to card effects to destroy it. Second, to get the most out of this card Hidden Armory has to be run, and that hasn't happened since Snatch Steal was returned for one format. Third, you MUST pay the 500LP to put this either on top or bottom. While running Hidden Armory can help throw stuff into the grave and can be worked into a strategy, being forced to pay a minor cost to not even add the card to the hand is annoying. If it was to the hand it would be fantastic, but instead it takes an MST or monster effect to wreck whatever you were planning. If you throw it on top of your deck, you delay what you will draw next, if you put it on the bottom of your deck, you are going to have to search it again. If you have cards like Hidden Armory teched into your deck, then it doesn't make sense to play more than one of this card.
 
I think it is a good card to use, but I don't think it will be game-breaking enough. There's too much destruction in the game right now and having to research this card over and over (or delay your own draw) isn't great game mechanics. It would've been better if the LP cost were higher (say 1000LP) and to add to the HAND instead.
 
Advanced-2.5/5
Art-3/5
 
Until Next Time
KingofLullaby