Video version
For those that prefer watching the guide in video version:
Reroll methods
Salted emails
Important! Google email accounts are highly recommended for rerolling. This is because Gmail accounts can abuse the salt system, which basically allows you to use the same e-mail multiple times for registration.
To use a salted email, you add a +anything between the name and the @gmail portion of your e-mail address. For example, if your gmail account name is myname@gmail.com, a salted e-mail would be myname+anything@gmail.com.
The string behind the + symbol can be any letters or numbers of any length. Still, to easily keep track of rerolled accounts, we recommend using numbers. Any e-mails sent to a salted e-mail will be redirected to the email without the salt used.
If you're super serious about rerolling, we suggest to create a sheet or a txt file where you will track what salted account got what pulls.
When you first install the game, press the Create Account button.
Then, enter your email and password (to clarify: not the password you use for your email, but one you want to use for the game), but at the end of the email add +1. This will be your first rerolled account and let's hope the number never goes into 3 digits and the RNG will be on your side.
Here's how the salted email should look like on your second run.
Once you're done with the reroll (the process itself is described below), navigate the Menu screen and press the Account button.
The next screen will have a Log Out button that will take you back to the lobby and you will be able to create another account - just change the number at the end of the email.
With this method, not only you're keeping all the accounts you've rolled and can come back to them at any time (when you for example have enough of rolling), but also it's the best method for those with limited internet transfer, as it means you just have to download the game once.
File manager abuse
Sadly after the recent ban on emulators, the File manager abuse no longer works.
Reroll process
One reroll in NIKKE takes around 10-12 minutes so it can be said it's average compared to other games. Sadly, you are forced to play through the tutorial without the ability to skip any parts - also auto-skill and auto-aim features unlock after you finish the tutorial and gain freedom of movement, forcing you to manually play the few battles in Chapter 1 every time.
Basically, just do what the game tells you to do till you reach the point around the 10 minute mark when you finish Chapter 1 and the game will ask you to do your first 10-pull. The tutorial 10-pull guarantees that you will receive one SSR rarity character (You can only get one SSR on tutorial pull. No more, no less.).
What's great is that the tutorial pool isn't limited and you can obtain ANY SSR Rarity character from the three main factions - only Pilgrims and event-limited characters can't be pulled.
Once you do the tutorial pull, it's time to gather whatever rewards are currently available in your mail if you haven't already - sadly, compared to the early days, most likely you won't be able to get enough Gems to do another 10-pull. You will have to play a bit more and reach and clear Stage 2-1 in Chapter 2 to get enough Gems to do another 10-pull (and this is where you can get a Pilgrim Nikke). For reference, you need 3000 gems for a 10-pull in Nikke.
Hence, the reroll process will be to keep an account till you do 2 10-pulls (total 20 pulls), in which the first is the tutorial 10-pull, and the second 10-pull is after you beat Stage 2-1 in Chapter 2, where we aim for a Pilgrim nikke.
Our aim is to get 1-2 Meta Nikkes till this point (Ideally Red Hood or Modernia). One Meta Nikke is enough. If you don't get one of the Meta Nikkes, you repeat the process with a new salted account till you get one. Once you get the nikke you want, you are now done with rerolling!
Extended Reroll
These rerolls are focused on improving the quality of each reroll, but require more time to execute than the process described above (usually 30 minutes per reroll). We will be trying to maximise the chance of getting a Meta Pilgrim specifically, since all of our pulls will have a chance of dropping a Pilgrim.
We will repeat the same reroll process as described in the previous section, but our pull management will be different. After finishing Stage 2-1, the tutorial ends. Now, we will go to the recruitment area and completely SKIP and NOT PULL ON the tutorial banner. This is important for several reasons. The tutorial 10-pull can only gives 1 SSR, and has no chance of dropping a Pilgrim. Instead, we will be unlocking Ordinary Banner (process on how to unlock this Banner is in the next paragraph) and spend our 10-pulls there, since on this banner we can get possibly get multiple SSR AND Pilgrims! Both Tutorial Banner and Ordinary Banner use the same resources! So don't get tricked into pulling on Tutorial Banner!
To continue, after finishing Stage 2-1, we will go to the recruitment tab and use 3000 gems we have accumulated to 10-pull on the Special Recruit Banner! This is an exploit which will allow you to unlock the Ordinary Recruit banner and spend the Tickets you were supposed to use on the tutorial 10-pull on the Ordinary Banner! Thanks to discord user tessa7883 for sharing this with us!
Now, after doing all of this comes the extension of the old reroll process. We urge you to push campaign and finish chapter 2, and also enter Active CD-Keys that are present.
This will give you a bunch of extra gems, roughly 10-15 more pulls, and will take roughly 15 minutes to execute. The gems you now have can be spent on Special Recruitment Banner or Ordinary Recruitment Banner, whichever one you like! The chances of getting a pilgrim are equal on both banners. You can check the rates of getting each Nikke in the info box they provide.
This in total will give you 35-40 pulls per reroll in 30-35 minutes, and will greatly improve the chance of you getting your favourite nikke, especially pilgrims!
Who to aim for?
We know how the reroll process works in NIKKE, and the only question remains is who should we reroll for. If you want to make your own choice, check our tier list - click on any character you fancy and check her review.
Now let's move to reroll goals.
Nikke teams at minimum require 2 Burst 3 units, 1 Burst 2 Unit, and 1 Burst 1 unit as a minimum. This anniversary you possibly have a chance to get at least one meta unit of each category, but beware: Most of the recommendations will be Pilgrims, who are extremely hard to get!
Burst 3 Targets
These are your reroll aims. All 5 of these Nikkes are immensely Meta units that you should reroll for! If you can invest time into rerolling, we recommend aiming for one of these 5 units from a reroll, and then spend the rest of your time pulling on the current rate up banner if the unit is well rated by the community, so that you may get her as well! This should give you an extremely easy start to campaign. You can check the rate up banner's ratings if our review is up, or just join our discord server to confirm any doubts you may have!
Something to keep in mind is that Vesti: Tactical Upgrade can also be obtained from the tutorial pull since she is not a pilgrim. She is the only non-pilgrim Nikke that is good to reroll for since she is proven to be excellent in the Campaign game mode, which is the main attraction of Nikke.
Burst 2 Targets
These 2 are currently the strongest B2s possible, with Crown having an edge over Grave. Nevertheless, rerolling for them is worth it, especially for Crown since she is considered the best unit in the game by most players.
Burst 1 Targets
Nikke has released a limited time bonus recruit system in ordinary banner, where you may spend 100 pulls and get a confirmed meta SSR pick between 
However, while rerolling if players want to pull for an even better B1 unit, they can choose to aim for Siren (who is known as Little Mermaid in-game). Beware that she is also a Pilgrim unit, which means she is much harder to get than Liter.
Support alternatives
Some other good alternatives in the support role are as follows:
Among these characters, all can be obtained from the tutorial pulls! Also, if you decide to reroll for
General alternatives
Some units may not be super meta, but they can help progression at the very least. They don't need to be paired with anyone and can work alone. Remember that if you are going for ideal rerolls, these are not the correct units. These are just the alternatives.
Summary
Overall, if you just want to aim for one Nikke, we recommend aiming for one of the Burst 3s. But if you are a passionate perfectionist, aiming for 4 meta units on one reroll is as easy as it has ever been in Nikke's history in the upcoming anniversary, since multiple pilgrim banners will be on rate up! We hope you have a good rerolling session!