Complex sentence: Upon hearing what happened to Stark Tower during the fight with Ultron, Ant-Man allows Iron Man, Hawkeye and Thor to use his lab within an anthill and is shown to have an A.I. named J.O.E.Y. (his own version of J.A.R.V.I.S.).
Split into simpler sentences: Upon hearing what happened to Stark Tower during the fight with Ultron, Ant-Man allows Iron Man, Hawkeye and Thor to use his lab within an anthill. His lab is shown to have an A.I. named J.O.E.Y. (his own version of J.A.R.V.I.S.).