I decided to write this guide on beating return, due to the recent influx of new players, and remembering how annoying return to play against when I was new to alteil. This guide talk about three things: 1) What is return, 2) How can I beat it 3) Examples of beating it (I'm looking for donations of videos that showcase beating return, so if you have any, it would be greatly appreciated).
A lot of the reasons that people feel frustrated playing against return is because it plays on poor understanding of game mechanics, strategy, file composition, and exploits them. It's important to understand learning how Alteil works is just as important as learning "How to beat files that use return".
I'd also like to point out the title of the guide. I wrote "Beating files that have return", because it is important to remember that you are not playing against the return mechanic, which is a mechanic, and thus cannot be defeated, but playing against the "file that has return mechanics in it", and "the players that use return", which CAN be defeated. Mechanics are a combination of rules and code, alike gravity, and thus pointless to fight against, because they simply are. What we seek to do is win, and what we must defeat are the files that use return, which have limitations and are not perfect or omnipotent, or players, who may have flaws we can exploit.
1) What is return?
Return is a mechanic that "returns" a unit on the field to your card file. These mechanics usually cost as much SP as the level of card that is returned (but not always). There are three important effects of return that you should be aware of, and prepared for: 1) You lose the field presence of the unit that is returned, 2) You lose the SP you used to play the unit in the first place, 2) You lose whatever buffs that were on the unit in the first place.
In addition to simple returns like Return and Sweeping Tidalwave, you also have to deal with cards like Cyclone, which returns all level two or lower units, Wrath of the Sea Lord, which can return a level four card at the cost of one SP, soul skills like Song Sorceress, and units that can return other units like Witch.
This guide focuses on Return and Sweeping Tidalwave, because that's what most people will be facing and what will be most frustrating at lower levels.
2) Beating return.
In order to counter return, you must create solutions to all three of the effects that returns create, then combine your solutions in a viable deck. I will give example solutions to these three effects, but keep in mind that these are not ALL the solutions, and putting solutions together into a viable deck returns thought and practice.
Problem One: My unit is returned and now their field of units can beat mine
Solution A: Make a field that it doesn't matter if one or two cards are returned. This is the most intuitional and thus, most common solution to the first problem. It depends on fielding units strong enough that they can always beat any falkow cards that are on the field. For example, Folrart guardian can easily defeat any number of weaker falkow units by herself. It can also mean fielding units that do not depend on card synergy to work well. Units like Crest Halberd Soldier and Lebeau will always deal damage as long as they are on the field.
Solution B:Exert field control in other ways besides units. No matter how tanky the are, units are quite fragile and easily destroyed (unless you're playing big refess, of course). Grims, and soul skills can kill many units at one time. SP control is a power tool against falkow return files which must use SP on grims. Don't limit your perspective by believing things to not be possible.
Problem Two: You lose the SP that you put into that unit
Solution A: Use SP generating SS and units. SP management is a important part of Alteil, and playing return it is even more important, because SP dictates what you can do with your file. Would you rather have nine good cards, but only be able to use three of them? Or have six good cards and 3 SP gen cards, but be able to use all six of them? Six is greater than three, it's simple mathematics.
Solution B: Conserve SP where you can. Do you really need to revive that Unit? Can you make do without using that grim? Is it really important that you use that ability right now? It may be tempting to built up as large a field as possible, spam as many spells and abilities as you can and hope your opponent will be buried under the weight of your spells, but the best files use only as much SP as they need, no more no less. Building your file to use SP efficiently makes it faster, stronger, and last longer. A common trick is to kill a unit, then return it when your opponent revives it. That way, not only is it removed from the field, your opponent has spent one SP reviving it.
Problem Three: You lose buffs on/from the unit returned.
Solution A: Do not over rely on them. It's nice to use buffs, but it's important to remember that besides return, there are plenty of removal, destroy, or lockdown mechanics in the game. You need to strike a balance when using them. For example, when to use them and how to use attack buffs should depend heavily on how much you can use them: It wouldn't make sense to give a salamander a +30/+30.
Solution B: Defending against returns. There are a few ways to avoid some nasty returns. The first is leveling a unit with spells or effects. This works against Returns that have level restrictions. Cards like miracle fruit and the fate of esria can give a temporary boost to units and stop Returns from effecting them. But be warned, revived units don't have their previous live's levels. You can a kill returning units with pinpoint cards like Archer Captain/Fistara, or cards that can attack back rows, like Giant Tiger. Use Faerie Blessing or Pixie Messenger to prevent being engaged. There are many possibilities, just be creative!
3) Examples :
Card files:
The Lunar Battalion

This is a file I developed while I was trying to find a use for the new Set 11 Cards. I tried to make it with no rares or EX cards, and the highest rarity card is two Lion General/Zagar, but you could easily replace him with King of Mankind/Verlaat, OR Veteran Folrart Paladin. The crux of the file depends on the synergy between Folrart Guardian and Moon Child/Miffyre, but the rest of the file is easily changed or reconfigured to your liking.
This file is centered around cards that are difficult to return, generate sp with no conditions, and does not over rely on buffing. Each card fulfills a specific role in a built up field, but every unit is strong enough without other cards to support them.
Some things to note: Two things I noticed while building this file was that you will want A) a unit that can pinpoint cards, which is fulfilled by Girl Combat Priest in this file, but could be exchanged with Folrart Griffin Knight, and B) A soul skill that engages enemy units, which gives you time to build up your field.
Pixies files:

I was a little hesitant to put down pixies because they are finicky to play, but despite all the nerfs, they are still a strong tribe with a good balance of strengths and weaknesses. I wrote a small guide on them, if you're interested.
Pixies are a little mix of everything: They are an efficient rush file, with elements of control, using tribal buffs and soul skills to dominate all kinds of files. Pixies actually have an advantage over files with return because Pixies GS prevents their play.
For their soul skills, you can generally use anything, but I find that Fierte pretty much trips up everything except lycans. So.... take the time to learn pixies. They're pretty good.
Videos:
Feedback and donations to the examples section appreciated


