Skill Borrower

Skill Borrower is just a cool 3 mana creature if you ask me. Sure, she gets some cool skills if your next card is an artifact or a creature. Think of her as an additional Obelisk, or Capsules? Or even Bloodpyre Elemental? Lol. All in all, I think she's a great card to have if you have nice creatures with activated abilities. But then again, she can only use it for one turn before you draw it. So.. her usage is really really limited.

Sealed Strength - Use her if you're heavy on Blue and creatures with activated abilities. She's not much but still useful.

Draft Strength - Not exactly a first pick material, but she can be good. Take her home early cause she ain't staying long.

Constructed Strength - Ravager anyone? Lol

Sharding Sphinx

Sharding Sphinx is one of the most sought after cards in the rare region. True that it needs 2 Blue mana but it's a 4/4 flying factory! It's totally worth the casting cost.

Sealed Strength - Use it if you have decent cards in Blue!

Draft Strength - First pick material but you might not want to hate draft it cause it's not the most terrifying thing ever.

Constructed Strength - At 6 mana it's a bit expensive for Blue especially in Standard. But I guess Block Constructed would be more acceptable if you ask me.

Mindlock Orb

Mindlock Orb is a typical Blue card which restrict things from happening. Unfortunately it doesn't exactly do much for 4 mana casting cost. A crap rare if you ask me. Very crap.

Sealed Strength - You've got a useless rare in your pool.

Draft Strength - Fucking pass it!

Constructed Strength - I still don't see why you should run this unless you're up against Battle of the Wits?

Memory Erosion

Memory Erosion is a mill card obviously. A 3 mana enchantment that mills your opponent whenever he plays a spell? Nice. But think again, in Standard or even Block, the amount of mill cards are way too little. Thus, this card is going to be quite useless most of the time. :(

Sealed Strength - Low strength. Very low. Milling is exactly the thing you wanna do in this format.

Draft Strength - Pass it. As I've said, milling is not advisable as far as the current format is concerned.

Constructed Strength - Maybe Extended?

Master of Etherium

Master of Etherium is obviously an awesome card for artifact decks. I'm sure the extended Affinity decks smiled when they saw him. For a deck filled with artifact lands, when he hits play alone, he's already a 4/4. What else? He boosts all his comrades with extra +1/+1. Definitely great. But in terms of Limited format, he's a combo card. Doesn't do well on its own, but works great if you are heavy in Esper creatures!

Sealed Strength - Check your pool. If you have at least 8 playable artifact creatures, then run him. Else wise, ignore.

Draft Strength - See yourself going Esper? Pick him up. But don't do anything silly if you're not heavy on artifact creatures and artifacts.

Constructed Strength - Affinity is so going to love him!

Kederekt Leviathan

Kederekt Leviathan is not that impressive. Sure, it bounces off everything in play when it hits play, but he requires 8 mana for him to do so. For blue, especially in Limited, it's way way too late and most blue mages would have been dead by then. Not highly appreciated, but should it hit board, it's going to be very tactical for the caster.

Sealed Strength - Pack him in your Blue based deck as he may help to clear annoying threats.

Draft Strength - Not a first pick material, but can be useful if you're in Blue.

Constructed Strength - You can forget seeing him in any Constructed format.

Gather Specimens

Gather Specimens is a very expensive 1 chance instant Persuasion. It cost 1 extra blue mana which is definitely hard to achieve in Limited Format. I personally dislike this card a lot, but it can sometimes be useful for you to hijack some of the late game fatties.

Sealed Strength - You have to evaluate your pool. This card is not necessary in your maindeck even if you're playing blue due to the fact that it requires 3 blue mana.

Draft Strength - Not highly sought after but good to pick it if you feel like you're heavy in blue.

Constructed Strength - Forget about seeing him at all.