To merge duplicate units in Defend ur base with anime , drag one fighter onto another fighter that has the same name and the same mutation. The game consumes the copies and upgrades the surviving unit with better stats, and some sources note that a unit can be merged up to Level 7.

Merge rules

  • The two units must match by name.
  • They also need the same mutation ; a Gold version will not merge with an unmutated version.
  • If the units differ in mutation, the game treats them as separate even if the character is the same.

How to do it

  1. Open your unit grid.
  2. Pick up one duplicate unit.
  3. Drop it onto the matching duplicate.
  4. Confirm the merge if prompted.
    This is the same basic behavior described in the game guides and clone-machine explanations.

Quick example

If you have two Diamond Tenpachi units, they can merge together, but a Diamond Tenpachi and a regular Tenpachi cannot.

Useful tip

If you want to merge faster, focus on collecting matching duplicates of the unit you actually plan to keep, because spreading upgrades across too many different fighters slows progression.

TL;DR: same unit name + same mutation + drag one onto the other = merge.