Epic War 2 Edit
In Epic War 2, revenge waves start on stage 7, and if the player has already beaten stage 18 (the final stage) they can use Flame Devils to conquer it. If the player hasn't beaten stage 18 yet, then they can use Titans or spam with Paladins, Protectors, or Beast Riders; preferably with mana maxed out. Angel Knights can also take them on, but it is not possible to unlock them before beating stage 12, as the player must max out and unlock the research tree for all three races and to unlock the third race (the orc race), the player must beat stage 12.
Epic War 3 Edit
In Epic War 3, revenge waves start when the player's hero is at level 3. Revenge waves can be easily conquered with the Phoenix Strike, other spells can also help for a while (such as the Hercules Strength). Early on the player can also conquer it by just having everyone go out, provided that they are properly equipped. In Trial 4, the player should have all units fall back every time the alarm goes off, and should have some titans (recommended two) that stay back but help fight off the revenge waves, the main boss, and everything after the last (third) revenge wave.
Epic War 4 Edit
Epic War 4 introduced a difficulty setting with Normal, Hard, and Epic difficulties for each stage. Revenge Waves are on Hard and Epic, but not on Normal. The player can farm before playing Hard or Epic if they don't have invincibility maxed out, and then wait near the castle (but not so close that units attack it, just so that they keep back enemies) until their mana is at least 200 (if not there already), then attack the castle and reuse invincibility when the invincibility counter gets to 2, until either the revenge wave is defeated, or the stage is completed.
Epic War VI Edit
In Epic War VI, revenge waves are usually strong enough to quickly kill most or all titans, but these can be conquered if the heroes, units, and spells are strong enough, and the player has everyone go out while using all spells available. The player can get more crystals if they are not strong enough.