BABY AVENGER

According to the few investigations that have been done, it seems that Hydra has been releasing an impossible-to-perceive gas and is causing several S.H.I.E.L.D. agents. and even Super-heroes become Littles, which makes them vulnerable and Hydra is leading the way, because one of the best and most skilled agents has been affected by the alleged gas and he will not be the only one. But....Could it be a gas that is affecting them?
*The characters are not mine, it's just a fanfic (although there are some invented characters that do not exist in the UCM)*