4) LEONARDO DA VINCI
Polymath, artist and inventor in our world, the Marvel 616 version of da Vinci was also the founder of a secret society known as The Brotherhood Of The Shield, dedicated to protecting life on Earth. Mastering time-travel, he traveled forward to the 1960s and caused a rift in The Brotherhood that led to the formation of Hydra, The Zodiac Cartel…
…and S.H.I.E.L.D.