Also known as: CrossSystem, Cross_System, ソウルユニゾン, クロスシステム, クロスチェンジシステム
Known as Soul Unison in Japan, it is an ability of MegaMan.Exe where he takes the appearance and abilities of other NetNavis.
This tag also applies for the https://megaman.fandom.com/wiki/Cross_System mechanic from Battle Network 6 as well as fan concepts.