Juno's Gladius

Juno's Gladius is a Roman sword owned by Hera's Roman form Juno.

The Lost Hero
Jason's magical coin, Ivlivs, was destroyed in a quest to save Hera from Gaea. However, after the quest was finished and Hera was released from her cage, she appeared before Jason. Hera, who felt responsible for Jason's loss and being his patron, gave Jason her sword. He accepted it, but so far he hasn't been seen using it in the series, leaving any special powers the sword may have unknown.

Disadvantages compared to Ivlivs
Since Jason no longer has a lance or weapon of similar length, he likely has no way to control and aim the bolts of lightning that he can call down from the sky. It is possible however that with practice he can direct lightning without the use of a long weapon, but given the amount of time Jason has had to hone his powers, it is unlikely. Aside from that, there is also the disadvantage of being unable to disguise it as something more common.