Answer: it depends on the dupe. Most of the time, you’ll be using them as skillups. As with anything, though, there are exceptions. The unit “most worth duping” is probably Lushen – the Wind Joker. Most other units can be used for skillups, and your chances of pulling a dupe 5* are pretty slim.
Use Dupes for Skill-Ups
Most of the time, you’ll be using dupes for skillups. When you feed a monster of the same type (even if it’s a different element), the upgraded monster will receive a random skill-up. This is especially important for 3* monsters. Not only will you get a ton of them, but some of them are really important. For example, despite this account only being a few weeks old, Bernard (Wind Griffon) has almost maxed all his skills – and Bernard is a very important monster for both PvE and PvP. Even then, if you accidentally get rid of an important 3* Monster, you’ll probably get more of them– except for Light/Dark monsters. 4* Monsters are a different story. Some 4* Monsters are also very important, but getting the specific one you need can take a LOT of time. Since Summoners War receives regular balance updates, it’s best to keep at least one copy of every 4* Monster– you never know when one might become meta. Most of the time, 4* Monsters can also be used for skillups. There is one huge exception to this though. You want to keep two copies of Lushen, the Wind Joker. His third skill, Amputation Magic, is one of the strongest skills in the game. It ignores defense and hits all enemies. In most cases, having 2 well-built Lushen’s is the key to getting Giants runs to under 1 minute. There’s a few other 4* Monsters that are important, but they’re not so important that you need multiple copies of them.
What About 5* Dupes?
Just to be clear, your chance of getting a 5* dupe as the average player is abysmally low. Not only are there a LOT of different 5*’s, there’s three different elements, too. It still can happen though. Whether you keep a 5* dupe depends on what they do. For example, if you pull two copies of Woosa (Water Pioneer), it’s recommended to keep both of them. The reason is his third skill. In some cases, you’ll want him to go first. In other cases, you’ll want him to go last. Because of the high cost of rune removal (and the fact that it’s just generally annoying), keeping both is a good idea. If you summon a dupe you don’t need, though, you can break them down into Ancient Crystals in the Crafting Building. Here’s how you can do that: First, go to the Crafting Building. Next, tap on the “others” tab at the top. From here, tap on this “Ancient Crystal” option. It’ll look like this: I’m not going to do it because I don’t have any dupes, but you can spend Ancient Crystals in the store. Most players won’t be able to make use of this, as losing a 5* in the process is a really steep price.
