Kazierts, I agree that both Faerie Mastermind and Spectral Sailor are excellent creatures, but why do you not believe that Triskaidekaphile is a good creature? It provides four benefits in one card: unlimited hand size, a mana sink, repeatable card advantage, and an alternate win condition, all for a mere 2 mana, so how is that not a staple for every blue deck?

TheOfficialCreator, I have noticed that, in most cases, except that Shared Summons is not as efficient as is Eladamri's Call, and I also would prefer Opportunity over Overflowing Insight, because the former card is an instant, while the latter card is a sorcery, and that difference can be crucial in a desperate situation.

TheOfficialCreator, I agree with that, and, as I said, it was the most difficult card in this cycle to design, so I shall definitely redesign it, soon.

I have replaced Boros Charm, Izzet Charm, and Grand Arbiter Augustin IV with Prismari Command, Prosperous Partnership, and Sunhome Guildmage, which improved the color balance of this deck, because, as great as were, I feel that the newer cards are better suited for this deck.

I have replaced Sunder Shaman with Atalan Jackal, which reduced this deck's average converted mana cost from 3.81 to 3.79, because, as great as the shaman was, this deck definitely needs mana acceleration, and it also has plenty of other cards that can destroy artifacts and enchantments.

I often wonder which is more important for a card: its overall cost or its cost-to-effect ratio (i.e., its mana efficiency); for example, there is no question that Lightning Bolt is superior to both Shock and Searing Spear, but, between the other two cards, I would choose Shock over Searing Spear in the majority of situations, because Shock has a ratio of 2 damage for 1 mana, whereas Searing Spear has a ratio of 1.5 damage for 1 mana.

For a slightly more complicated example, compare Eladamri's Call to Shared Summons; the former card can find a creature for a mere 2 mana, which is very efficient, but it simply replaces one card in its controller's hand with another, whereas the latter card can search for two creatures, which leaves its caster with an additional card in hand, compared to before it is cast, but it is less efficient, costing 2.5 mana per creature found, so it is not as clear which card is superior, there.

Opportunity is literally a double version of Quick Study, as they both have the same ratio of cost to effect, but which is the superior card? Is it really better to spend six mana to draw four cards, as doing that would leave the caster with less mana to cast the spells that they draw? Also, Quick Study is strictly better than is Inspiration, as it costs 1 less mana to cast, but, between Concentrate and Tidings, I am not certain which is superior, since they both allow a player to draw one less card than their mana values.

On the subject of card drawing, in the realm of repeatable card drawing, Arcane Encyclopedia is strictly better than is Jayemdae Tome, as it costs only 3 mana to draw a single card, compared to 4, but Tower of Fortunes can draw four cards for 8 mana, which is a ratio of 2 mana per card, but that ability costs 8 mana, overall, so the question is if it is worth 8 mana to draw four cards.

Continuing that theme, there are numerous creatures (and one enchantment) that allow a player to repeatedly draw cards, such as Azure Mage, Spectral Sailor, Faerie Mastermind, Triskaidekaphile, or Treasure Trove, a ratio of 4 mana for one card, but Mystic Archaeologist can draw 2 two cards for 5 mana, a ratio of 2.5 mana per card, which is definitely far superior, in my mind.

Hedron Archive is literally two Mind Stones put together, and Dreamstone Hedron is literally a triple Mind Stone, so they all have the same cost-to-effect ratio, but I prefer the original Mind Stone, since the existence of Thran Dynamo and Gilded Lotus makes it difficult to justify using the other mana rocks, at least, for me.

To use the example of Skyward Eye Prophets, a 1/1 creature for 2 mana is perfectly acceptable, a 2/2 creature for 4 mana is slightly expensive, but nothing outrageous, but a 3/3 creature for 6 mana is simply too much, although, as a side note, I have a copy of that creature, in one of my decks, because I really like its ability.

For a further example, I would choose Mantis Rider over Lightning Angel in the majority of situations, since it provides a better rate than does the angel, and, similarly, I would choose Wilt-Leaf Cavaliers over Vernadi Shieldmate, since the former creature is more efficient for its cost.

I believe that I have provided a sufficient number of examples, for this discussion, so which trait do you believe is more important: overall mana cost or cost-to-effect ratio/mana efficiency? I certainly am interested to hear your thoughts on this matter.

Bookrook, why do you believe that?

Also, this deck has only a minimal amount of token generation, but plenty of lifegain, so I believe that the crusade is better in decks that generate plenty of tokens, which I do have.

Bookrook, that would increase the average converted mana cost of this deck, and I have that card in every EDH deck of mine, for a reason.

Kazierts, if I do put a mana dork into this deck, it most likely would be Enduring Vitality, because that creatures turns all of my creatures into mana dorks; what do you say, about that?

Also, do you believe that Heroic Intervention is a good card, for this deck? It is redundant if I copy it, with Riku, but, given that my opponents shall almost certainly attempt to destroy Riku, after I summon him, I likely should have a method of keeping him safe, in such situations.

Kazierts, this deck does not have a strong focus on dinosaurs, so I am not certain about Marauding Raptor or Intrepid Paleontologist.

I definitely considered putting Dryad of the Ilysian Grove into this deck, but this deck has very few, if any, cards that care about basic land types, and I also need to be careful about putting too many creatures into this deck, since each additional creature is one fewer card that shall synergize with Wandering Mind.

This deck already contains a copy of Terror of the Peaks, and I have no problem with removing Ionize, so what would you recommend as a replacement, for it? I do need to keep at least several counterspells, in this deck, as it is a blue deck.

I have replaced Marshal's Anthem with Flowering of the White Tree, which reduced this deck's average converted mana cost from 3.87 to 3.83, which is very nice, since the anthem required too great an investment of mana to be used to its fullest potential.

Bookrook, yes, that is true, but I am no certain what card I would removed, to make room, for him, since every card in this deck is fairly well-suited for it, already.

Bookrook, I am very fond of Archangel of Thune, since this deck has plenty of methods of gaining life, to trigger her ability.

wallisface, thank you, very much, and I am very glad to know that, although I am not happy, about it, since I was hoping to be able to bypass effects such as Grafdigger's Cage, if my opponents use that card.

Kazierts, thank you, very much, so I shall certainly consider several options, for that deck.

I am considering replacing the copies of Arcane Signet and Commander's Sphere that are in my Riku of Two Reflections EDH deck with cards that allow me to search my library for lands, most likely Farseek and Cultivate, because of the great synergy that those spells have with Riku, but I first would like to ask everyone else here for advice, about that, before I make any decisions, on this matter.

What does everyone else say, about this? Should I replace the mana rocks in my Riku deck with spells that search for lands, instead?

Bookrook, both of those creatures are amazing creatures, but they are very expensive, so I am not certain if I can reliably cast them; Gisela is my general, so I am not worried about being able to cast her, but there is no guarantee that I shall draw either of those cards in an average game.

I have an EDH deck with Meren of Clan Nel Toth as its general, and, in one game, one of my opponents controlled a Grafdigger's Cage, which would have prevented Meren's ability from returning a creature from my graveyard directly to the battlefield, so I instead returned the creature to my hand, when here ability triggered (the creature's mana value was less than or equal to the number of experience counters that I had).

Was that a legal play? I sincerely hope that it was, because I would like the assurance that I can bypass attempts at hindering my deck's strategy.

Bookrook, that is an interesting suggestion, as Gisela would prevent the damage that that artifact would deal to my own creatures, but we still have not reached a conclusion about which card I should remove, to make room for a new card, or if I even need to put that card into this deck.

I have replaced Black Market Connections with Widespread Thieving, because this deck does not have a sufficient amount of methods of gaining life, to offset the life loss from the former enchantment.

veritablecvn, I can understand that, but I like having an even number of lands in my deck; I know that that may be irrational, but it is one of my idiosyncrasies.

FormOverFunction, that is definitely an excellent suggestion, but I would like to receive responses from several more users, before I make my final decision, on this matter.