Charming Prince is great in this deck because he has three options to choose from when he ETB's or flickers. We can Scry 2 to try and dig for combo pieces, we can gain 3 life if we're running low, or we can choose to flicker another creature if there is some value to be gained from doing so (which there almost certainly will be in this deck).
Cloud of Faeries at its worst is just a body on board that pays for itself because it untaps 2 lands when it enters the battlefield. However, in this deck, because we can blink it, we can untap 2 lands much more often. If combined with Brago and Strionic Resonator, we can use Cloud of Faeries to create infinite mana from our lands during any of our Resonator loops.
Spirited Companion is the first of our efficient card draw engine pieces. Every time we blink one of these with Brago, we will be drawing a card. With Strionic Resonator and a couple of mana rocks, we can draw our entire deck in one turn. See the Combos section for more details.
Wall of Omens plain and simple draws us a card when it ETB's and also provides a decent 0/4 body to block with.
Dawnbringer Cleric can remove any problematic enchantment when he ETB's. Useful for getting rid of stax pieces like Rhystic Study and Smothering Tithe or something really threatening like Aura Shards. The nice thing is that he has other beneficial modes that we can use if there are no enchantments to remove. Gaining 2 life if we have nothing else to do is always a plus and removing cards from graveyards seriously messes with any graveyard based strategies. Grave hate is annoying enough already but in this deck we can just keep blinking Dawnbringer Cleric whenever we want and stop A LOT of really good commanders from doing their thing (Meren of Clan Nel Toth, Muldrotha, the Gravetide, Sefris of the Hidden Ways, Chainer, Nightmare Adept, Karador, Ghost Chieftain, The Scarab God, I could go on).
Watcher for Tomorrow lets us look at the top 4 cards of our deck and choose one to exile when it ETB's. Once it leaves the field, we get to put that exiled card into our hand. This is fantastic with blink effects because we're essentially "drawing" a card each time it leaves and then looting 4 deep again when it re-enters the battlefield. Great value in this deck.
Priest of Ancient Lore plain and simple draws us a card and gives us 1 life when it ETB's.
Inspiring Overseer is just another copy of Priest, except it also has Flying for some cheeky combat damage.
Sea Gate Oracle gives us the option of picking one of the top 2 cards of our library and putting it into our hand each time it ETB's. A good way to draw a card but filter that draw so we're getting something we actually want.
Aether Channeler is such a fantastic card for any blink deck. He gives us the option to draw a card upon ETB, or bounce an opponent's non-land permanent. Removal or card draw are both fantastic options, if we don't need one we can just do the other. On top of all of that, we have the option to create a 1/1 Bird token. This guy gives us several options for when we go infinite with Brago and Strionic Resonator.
Circuit Mender is great value in a blink-focused deck because it has effects for both entering and leaving the battlefield. We gain 2 life whenever it ETBs and draw a card whenever it leaves. Simple effect but high-value in a Brago deck.
Welcoming Vampire is just a free card draw engine because once per turn whenever we have a creature with 2 or less power ETB under our control we get to draw a card. In a deck full of blinkers and lots of low-power creatures, this is a nice static effect that requires no mana and will simply draw us cards throughout the course of the game.
Reflector Mage can also bounce a creature but has the additional effect of barring opponents from casting anything with the same name as the bounced creature on their next turn. This restriction lingers even if Reflector Mage leaves the field, so we can blink it to bounce something else and prevent that from being cast as well, further restricting our opponents' options.
Skyclave Apparition can exile any permanent with CMC 4 or less when it ETB's. In exchange, when it leaves the field, the owner of that permanent creates a token with power/toughness equal to that card's CMC. A vanilla token is a small price to pay to get rid of something valuable on our opponents' field such as Phyrexian Altar, for example. Skyclave Apparition cannot blink tokens but we have several other cards (such as Aether Channeler) that can bounce or exile those tokens, effectively making them dissappear completely.
Loran of the Third Path is basically an upgraded Reclamation Sage, allowing us to destroy an artifact or enchantment whenever she ETBs. The fun part is her card draw ability, which allows us to draw a card but we also have to pick an opponent who gets to draw as well. We can leverage this as a political tool, making a deal with an opponent to help us out if we pick them to draw with us.
Recruiter of the Guard is mainly in here to find Cloud of Faeries since it alone can combo with Brago and Strionic Resonator. However, it can also find Archaeomancer or its backup Salvager of Secrets. It can also search our backup backup Venser, Shaper Savant. However, there are plenty of other valid tutor targets if the situation calls for it.
Trinket Mage lets us search for Sol Ring which makes a lot of our Brago combos with Strionic Resonator a lot easier to pull off. Alternatively, we can find Arcum's Astrolabe so that we have a repeatable card draw engine.
Tribute Mage lets us search for any of our color-producing mana rocks which enable our infinite mana combos with Brago and Strionic Resonator. Or we can search for Thought Vessel if we have a card draw engine going and don't want to discard to hand size. Alternatively, it lets us fetch Lightning Greaves in case Brago needs some extra protection.
Sailor of Means helps us ramp by creating treasures when it ETB's, however we can make this go infinite with Strionic Resonator, Brago and mana from mana rocks to create infinite treasures. Or if we have just available from a mana rock, we can still get infinite ETB's.
Glasspool Mimic
is mainly a utility creature in this deck because it can come in as a copy of any of our other creatures. This is particularly good in a blink deck because we can change it up and copy another creature if the situation calls for it. Aside from all of that, we have the option of playing this card as a land Glasspool Shore
if we just need the land drop instead. It's a flexible and versatile card in this deck.
Soulherder allows us one free flicker at the end of turn which is part of our gameplan anyway. Furthermore, it grows stronger for EACH creature that gets flickered so this thing can grow very large very quickly in this deck.
Thassa, Deep-Dwelling is mainly in here because she provides a free creature flicker at the end of turn. However if we manage to obtain 5 devotion to blue then she also becomes a formidable 6/5 creature with Indestructible.
Venser, Shaper Savant can bounce any permanent when he ETB's, making him a very versatile source of removal. Combo'd with Brago and Strionic Resonator, he can literally bounce everything our opponents control back to their hands.
Glen Elendra Archmage gives us the option to pay and sacrifice it to counter any non-creature spell. The nice thing is that it as Persist, meaning it can come back with a -1/-1 counter to let us do it again. Normally, this would be a 2-time use (because Persist wouldn't bring it back if it has a -1/-1 counter). But in this deck, we can blink it to make it re-enter the battlefield which gets rid of the -1/-1 counter. This means we can keep countering non-creature spells if we keep blinking the Archmage.
Preston, the Vanisher is insane in this deck. Preston creates a token copy of any creature that ETB's on our field (as long as it wasn't cast). We're playing a deck full of blink effects, so this ability is ridiculously easy to trigger. We blink any of our creatures and Preston will create an illusion copy of it when it re-enters, so we essentially double up on the ETB value, almost like Panharmonicon. The neat thing about Preson, however, is that he can pay just and exile five of those illusions to exile any other nonland permanent so he acts as removal as well.
Archaeomancer is mainly in here for combo purposes but it can also retrieve a lot of useful Instants and Sorceries if we need one. A Fierce Guardianship so we can protect Brago for free once again. Or perhaps a Swords to Plowshares if there is a problematic enemy creature on the board. Or maybe Supreme Verdict if we need to nuke the board.
Salvager of Secrets is a back-up Archaeomancer for combo and utility purposes.
Elesh Norn, Mother of Machines is a Panharmonicon on a stick. She doubles all of our ETB triggers. I shouldn't have to explain why this is good in a deck full of blink and ETB effects. Furthermore, she completely nullifies opponents' ETB effects, making her a formidable stax piece.
Peregrine Drake has great flicker value by being able to untap lands when it ETB's, helping us ramp and combo off.
Deadeye Navigator can soulbond itself to another creature when it ETB's. It then gives itself and that creature the ability to blink for . There are combos with this and Peregrine Drake that we can use to generate infinite mana but even paired to any other creature in this deck it's just good value.
Sun Titan is insanely good value in this deck because it can repeatedly reanimate 3-or-less-CMC permanents from our graveyard whenever it ETBs or attacks. Not only is this a repeatable way to retrieve our combo pieces but crucially it can grab Strionic Resonator (our most important combo piece) and the vast majority of the other permanents in our deck.
Combat Thresher has a deceptive CMC in this deck, because we can actually cast it for just for reduced stats but it retains its abilities. So for just 3 mana we get a 2/1 with double strike that draws us a card upon ETB, essentially making it a better Priest of Ancient Lore. However, in this deck, we can blink it which means it will come back as a 3/3 next time it ETBs, essentially bypassing the downside of the Prototype casting cost. At that point, it's a 3/3 with Double strike so it's formidable in combat and can deal 6 damage to an opponent when it swings unblocked.