'Once Upon A Time' season 5 episode 21 spoilers, plot news: A funeral is in order in 'Last Rites'

The heroes may have successfully returned to Storybrooke but Hades (Greg Germann) will make them feel like their hometown is no different than the Underworld in another exciting episode of "Once Upon A Time" season 5.
Emotions will run high in episode 21 of the fantasy drama titled "Last Rites" as Hades set out to kill one of Emma's (Jennifer Morrison) cohorts in the name of unlimited power that the mighty Olympian Crystal will give to him.
The synopsis for the next chapter of "Once Upon A Time" season 5 provides a clue one what may have led to that death. In the description of the episode, Emma and the rest apart from Regina (Lana Parilla) and Robin (Sean Maguire) try to find a way to beat Hades for good.
Hook (Colin O'Donoghue) also does what he can do from the Underworld. Robin and Regina, on the other hand, use a "direct approach" in beating Hades, which suggests that they are going after him themselves in their attempt to kill him.
Naturally, an "epic showdown" ensues and ends with the lives of the heroes "forever changed." And by forever changed, "Once Upon A Time" meant taking away someone from their lives.
According to Melty, it is highly likely that Robin gets killed trying to take down Hades and that the funeral in the upcoming episode of "Once Upon A Time" season 5. Many fans agree although some fear it is Zelena (Rebecca Mader), who Hades is only using to get to the Olympian Crystal.
Wielding the same weapon that he and the Wicked Witch conjured up as seen in the "Once Upon A Time" season 5 clip, Hades told his unseen prey in the video "This isn't going to kill you. It's going to end you."
At this point, no one is safe from the lord of the Underworld's wrath, although the promo shows that Emma and Regina are safe and are both devastated by the loss. Looking at their reaction, they lost someone really dear to them.
Who is in the casket? Find out on "Once Upon A Time" season 5 episode 21 "Last Rites," which will air on Sunday, May 8 at 8 p.m. EDT on ABC.