In death, they are united in a singular, benevolent purpose.
This deck runs as a sort of a hybrid between a tribal zombie deck and a token focus deck, using the Azorius colors. I've always been fascinated with the idea of zombies in a non-evil setting. This deck misses out on a lot of the tribal benefits that black color identity gives, I do believe I've found a deck that is both affordable and capable.
The idea here is simple enough: summon creatures, and sometimes discard them. Then, bring them back. The commander Temmet can use his embalm ability to enter the field repeatedly for a relatively low cost. The custom ordering works like this:
The Sacred Dead: These are zombie type creatures. Most of their effects either do with the graveyard, or with Azorius style support.
Born Again Zombies: These guys aren't zombies yet, but become mummies (another word for zombie, really) when they're summoned from the graveyard. These are good targets for "discard" effects, and as zombies they benefit from anything that improves zombies as well as anything that improves tokens.
Call the Undead: Through a variety of methods, these cards give you additional zombies, usually in the form of tokens but sometimes just through tutoring zombies you already have in the deck or graveyard. It might seem weird to bring back zombies from your graveyard as slightly different zombies, but it works out.
Zombie Tribal Empowerment: These cards boost the power of all your creatures. Sometimes it powers up zombies. Sometimes it powers up tokens. A lot of your creatures are both.
Azorius Control: I keep saying this is an Azorius deck and not just a blue/white deck, and these help enforce this theme. These cards are just meant to give your opponents a hard time.
Friends of the Dead: Some of these guys aren't zombies and never can be, but tokens are good in general in here, and spirits fit thematically if not mechanically, so they're here.
mana generation: Literally just cards that give you mana. Mana is good.
So that's basically all I'm willing to explain here. For the rest of this description, let's talk about Zombies across the planes, so you can justify why you're using zombies to your holier than thou friends.
Temmet and the Anointed
In the desert plane of Amonkhet, those that die come back as zombies, without exception. Yet, with enough care, it doesn't need to be so bad. The zombies of Amonkhet are simply serving an important role, even after death. Temmet, Vizier of Naktamun is in charge of these anointed mummies, leading the embalming process and also having command over them. He's a cleric rather than a necromancer, because his magic works very differently.
The Eternals are created by Nicol Bolas, and are essentially the anointed, but made with a legendary material that makes them stronger, more twisted versions of their previous selves. Their empathy and compassion are replaced by ruthlessness... But here we try not to think about that too much. Black color identity isn't allowed in a white/blue deck, but by the rules, tokens that aren't in the commander's identity are perfectly legal. It might help you sleep at night to tell yourself that Temmet has control of the eternals just like he does the embalmed. If that doesn't work, you can simply replace these cards with other embalm cards. They're not as strong, but it might be okay.
Stitcher Geralf and His Creations
On the plane of Innistrad, zombies can be made in several ways. Stitcher Geralf, in particular, makes his zombies (called Skaabs) using a combination of magic and science. This is less Immoral than it is amoral. Geralf in particular, while studying the undead, tried to make laws to warfare that protected the innocent. Geralf is mad, but he might not be bad.
It's worth noting that a lot of Geralf's undead required exiling creatures from the graveyard. These cards are pretty powerful, but the cost doesn't mesh too well with the emtomb mechanics, so I've chosen to avoid them.
Some others
Reef Pirates: Reef pirates is a much older card, and I have to assume it's a mono-blue zombie because they were afraid to make it multi-colored, and its "ocean" quality outranked its "zombie" quality. But, it's a blue zombie outside of Innistrad and Amonkhet, so I'm keeping it in.
Fatestitcher: You might assume that fatestitcher is one of Geralf's zombies, but actually this guy comes from the Shards of Alara, which was released a good few years before it. I'm not entirely sure why it's mono-blue, and since it has no flavor text all we can get is conjecture. Alara has only one other mono-blue zombie (which can't be used in this deck because of a white//black activation cast), which implies that it was created by Tezzeret, who normally is an artificer. Is fatestitcher another of his creations? Maybe! Who knows! I sort of hope not, because Nicol Bolas has his hands all over this very Azorius, very good aligned deck, and he shouldn't have more.
Phantom General: The phantom general is actually in the Ravnica block, which is nice. It's effect works more with the mechanics of Selesnya, but I'm inclined to think this is part of the Azorius Guild anyway, just based on its visual themes. Phantom General is a spirit and not a zombie, but it is also proof that Azorius and the undead can and do work together just fine.
Riptide Replicator: The riptide replicator is a device created by wizards in order to replicate the slivers, but it can pretty easily be modified to create all sorts of artificial life (though not so artificial that they are artifacts). In this case, Temmet has it rigged up to create zombies. How can it be a zombie if it was never not a zombie? Such are the great mysteries.
Quicksilver Gargantuan: Geralf may claim that zombies are more about their internal structure than they necessarily are about their status as "undead", and Quicksilver Guardian of Mirrodin affirms this, able to take the shape of a giant version of any creature on the battlefield. It's not always a zombie, but it can be.
Gods' Eye, Gate to the Reikai: This land, situated in Kamigawa, sometimes releases a spirit. This spirit is most likely related to the Kami, meaning they're not so much undead as they are supernatural.
