While nearly every version of Tony Stark seen in the multiverse has faced off against their own superpowered foes, each has also suffered from an unsettling family life. The Iron Man of the Ultimate Universe may be the epitome of that concept, as it was his own brother who proved to not only be his greatest adversary, but quite possibly the single worst threat to his world.
Source：https://www.cbr.com/iron-man-brother-ultimate-universe-marvel/
