One of the special traits of iron erens is the ability to chain attacks together to make combos. This is the basic pattern to make a combo: Regular attack -> Base eres -> Arcane eres
With this pattern, a single iron eren can rack up a number of hits on the enemy at once.
Iron erens don't have to work alone, though. Other erens can add their own eres to make even bigger combos. Here's how.
Set Senel, Chloe, or Jay as the leader, so you control him or her in battle. Set a shortcut to another character's eres. It's also a good idea to limit that character's other eres, so you have more control over how that character acts during battle. Now your erens are ready to fight.
Once in battle, corner or surround your enemy. Unleash a combo, and right as the combo is about to finish, press the shortcut to the other character's eres. If you time it right, that character's eres will then continue the combo. Once that eres is about to finish, use an eres of your own to keep the combo going. Keep doing this, and you can rack up hundreds of hits!
The more hits in a combo, the higher the bonus EXP you get after battle. Characters can also get special titles for high-hit combos. Mastering combos is a must for any true iron eren!