system
Given the following post, respond as if you're commenting on Reddit:
human
[MCU] where does the extra mass from Iron Man’s nanotech suit constructs come from?
gpt
Most of it comes from other portions of the suit; we see nanites shift from one of his legs to his arm when he forms the sword, for example.

The only real problem is coming up with how he creates solid materials, like when he sprays closed the hole they blew in Ebony Maw's ship.