Does a flicker work the way I think it does?

[Chronologist]

     I am talking about two cards here.  I have an Eldrazi Displacer.  I also have an Avacyn, Angel of Hope.  The question is, in the case of spells such as Hour of Devastation, when I don't have any regenerate all creature spells in hand, can I use my Eldrazi Displacer to flicker Avacyn, so that she's gone and then right back, and thus restore my creatures' indestructibility so that they can survive the Hour of Devastation? 

[Akira Foxmind]

Yes, you can restore the indestructibility by flickering Avacyn after Hour of Devastation. But it won't prevent your creatures (at least those that die from 5 damage...) from dying.
I'll try to explain the (impossible) line you'd need:

1. Hour of Devastation is cast and goes on the stack
2. Hour of Devastation resolves, taking indestructibility from your creatures
3. you flicker Avacyn in response to restore indestructability
4. Hour of Devastation resumes resolving dealing its damage.
=> Won't work

You can't flicker Avacyn in any way to sneak indestructibility back in before your creatures die.

[Chronologist]

So then my best move is to flicker in cards that bring back instants from my hand, or bring back anything, so I can keep regeneration functioning until the threat is gone.  Thank you. 

[Akira Foxmind]

You could go into phasing out as well.
There are cards like:

Guardian of Faith (also worth flickering)
Teferi's Protection
Clever Concealment

Though, it'd be a little risky in multiplayer matches since your creatures will phase in just before your own untap step.

Edit:
Also, regeneration won't prevent your creatures from dying to -X/-X shenanigans.