Free-Combination
From Transformers Wiki
Free-Combination (自由合体 Jiyū Gattai) is a special technique used by both Autobot and Decepticon combiners, allowing them to swap the component robots making up their limbs. It is different from Scramble Power in that it allows a certain level of autonomy to the individual robots, so that they can rearrange themselves when their unique skills are needed, forming special formations.
The only known Free-Combiners are Guard City and Battle Gaia. Operation Combination
