Why is there a "yo" particle and not a "ga" particle in the phrase "Yūsha Satan yo kiseki o okose!"


The phrase "Yūsha Satan yo kiseki o okose!" is translated as "Make a Miracle,
Satan the Hero!" or "Valiant Mr. Satan, Work a Miracle!" . Why is there a yo
particle after Satan and not a ga particle? Wasnt yo supposed to be an ending
particle for emphasis? What does it mean here?




I believe this is the vocative よ, similar in meaning and usage to the [English
O](http://mentalfloss.com/article/56582/whats-difference-between-o-and-oh).
EDict mentions this meaning:

> (2) (after a noun) used when calling out to someone
>
> `恋人よ、我に帰れ。` Lover, come back to me.

[Japanese Wikipedia](https://ja.wikipedia.org/wiki/%E5%91%BC%E6%A0%BC) has
this example from Latin:

> Quo vadis, domine? `主よ、いずこへ行き給う`

You could translate the sentence as "O Satan the Hero, make a miracle happen!"




I believe this is the vocative よ, similar in meaning and usage to the [English
O](http://mentalfloss.com/article/56582/whats-difference-between-o-and-oh).
EDict mentions this meaning:

> (2) (after a noun) used when calling out to someone
>
> `恋人よ、我に帰れ。` Lover, come back to me.

[Japanese Wikipedia](https://ja.wikipedia.org/wiki/%E5%91%BC%E6%A0%BC) has
this example from Latin:

> Quo vadis, domine? `主よ、いずこへ行き給う`

You could translate the sentence as "O Satan the Hero, make a miracle happen!"

