Basically, whenever you play a Spirit (or Arcane) spell, Tallowisp allows you search your deck for an Aura card and add it to your hand. So, does Tallowisp trigger itself? Sadly, the wording of its ability doesn't allow it to count itself when it enters the battlefield. This is because it already has to be on the board for its ability to take effect. However, Tallowisp has a 1/3 body, which is solid for 2 mana. The 3 toughness is relevant in Modern, which is a format with plenty of 2 power creatures.
Tallowisp is already a decent card on its own, and it calls for decks to be built around it. With U/W Spirits already a decent deck in Modern, it seems fair to see how a Modern Spirits deck built around Tallowisp and efficient Auras would work out.
There have been some successful deck brews in the past built around Tallowisp. One that caught lots attention was a Modern Bant Tallowisp Shoal deck that utilizes Shining Shoal and Unflinching Courage. As cool as it sounded, it wasn't really the flavor I was going for with our deck.
We wanted to keep the deck in two colors and make it purely tribal. At first, a deck which featured Geist of Saint Traft as the main creature. But as we look over the newer Spirit creatures, we'll see that we can take this U/W Spirits deck in a much different direction.
U/W Tallowisp Spirits & Auras (Modern & Casual)
4 Mausoleum Wanderer
3 Selfless Spirit
2 Spell Queller
3 Drogskol Captain
Non-Creature Spells (28)
2 Ethereal Armor
4 Path to Exile
3 Hyena Umbra
3 Azorius Charm
2 Steel of the Godhead
1 Angelic Destiny
4 Flooded Strand
4 Hallowed Fountain
4 Prairie Stream
Some Quick Thoughts on the Deck
While Geist of Saint Traft is great, running four copies in the deck makes it feel too one-dimensional. Yes, the Geist is hexproof, making him easy to load up with Auras. Also, the 4/4 Angel that you get when the Geist swings is nice. But building around him makes the deck very dependent on him, and therefore somewhat inconsistent. So, let's spread the Spirit love around!
Mausoleum Wanderer is really, really good. It's good against Burn and Control, especially when it grows to 2/2 or 3/3. As a consistent one-drop it can mess up quite a few decks. Heck, against Tron it can stop Ancient Stirrings! It's so versatile in the Modern format, and while people who have already played Spirits in the format know this, it's not really well-known JUST how good this guy is!
Rattlechains is sweet. Not only does he make you able to cast Spirits at instant speed (oh hi, instant speed Wanderer!) but when he comes into play, you can make a target Spirit hexproof. This is super important against all of the removal in the format.
Everyone knows how good Selfless Spirit is. Making your dudes indestructible is just really, really good.
Notice how all these Spirits so far have flying? That's awesome, because even though 1 or 2 points of damage doesn't seem relevant, it all adds up!
Tallowisp is the card that inspired this deck list in the first place. There were four copies in the list initially, but 3 turned out to be fine. The 4th copy was often redundant during playtesting. The tutor ability is extremely relevant and it was activated in every game in which I played this deck. Also, being a 1/3 means it walls 2 power creatures all day! Also, it's actually pretty good to suit up with the Auras, as I found.
Spell Queller was just too good to not include. Not only is he a quasi-counterspell, but a 2/3 flyer is awesome. I only needed two copies at first, but I may adjust this number later.
One inclusion that you probably wouldn't expect is Drogskol Captain. The cool thing about him is he pumps your other Spirits by +1/+1 and gives them hexproof. He doesn't give this to himself, but if you get two Captains on board, this deck becomes EXTREMELY hard to deal with. With everyone in this deck except Tallowisp able to fly, it's pretty awesome.
So what do we seek out with Tallowisp? There are two copies of Ethereal Armor and three of Hyena Umbra. The first strike is important in many cases and Ethereal Armor just gets better and better with each Enchantment you cast. The Umbra has totem armor, which gives your guys an extra protection against removal.
Steel of the Godhead is a two-of and it's the second-best equipment in the deck. While white creatures only get the lifelink, blue creatures are unable to be blocked. White and blue creatures get both abilities and an additional +1/+1 for each color. It's pretty awesome.
The last Aura is Angelic Destiny. While this is not a card you'd typically expect to see in Modern, it is relevant. Getting +4/+4 and flying is good enough, but you get first strike, too!
To protect our gameplan, we have Path to Exile to deal with problem creatures. There are 3 copies of Remand to keep up our tempo, too. I like these better than Mana Leak in this deck, as the extra card really helps. There are also 3 copies of Azorius Charm. I chose the Charm because of its versatility. It can draw you a card, give your creatures lifelink, or bounce a creature to the top of an opponent's deck. The lifelink really does matter, too, especially against burn and aggro.
The mana base is extremely simple. Prairie Stream is extremely good, believe it or not. You can even fetch it with Flooded Strand and the deck plays enough basic lands that it comes in untapped. I may adjust the mana base later on, but it seems pretty solid as symmetrical as it already is. Mystic Gate, the white/blue filter land, actually would probably be a good inclusion, but who wants to spend money on those?
This isn't a final version. It doesn't even have a sideboard! But it's already worked extremely well in playtesting. It would be worth tossing in copy or two of Threads of Disloyalty, which can steal creatures with converted mana cost 2 or less, into a sideboard. It's a nice target for Tallowisp to fetch. It probably also doesn't hurt to throw in a copy or two of Geist of Saint Traft. An Aura-based deck doesn't feel complete without him, although it seems to function well despite that.
While I'm not sure how it will hold up against the top 8 decks, it has a chance to win some games. For now, I'd say it's a purely casual deck. But it has the pieces to be a very, very strong Spirit deck. If you decide to play "real" U/W Spirits in Modern, this is a great starting point.