Show. Don't Tell.

I was thinking about my post from this morning about Tharizdûn, the Temple and various things that happened in the wee hours of history.
While I have a nice little mythology going here with bits that date back all the way to when I first started playing my players, my kids, do not have the same investment.

I told tell them the story of course, but that is just a story.
Then I recalled the old adage; "Show. Don't tell."

So via a dream or flashback sequence, I am going to have my players participate in the Dawn War.
Here they are going to be figures from that mythical age in the fight against Tharizdun.

Here is what I have so far. The participants in the war are Tharizdun, Orcus and Demogorgon, though he only had one head at this point. I will also have some of the other Elder Evils there too.
On the side of good are He Who Was (who will be killed here), Bahamut (as a PC), Samuel (a PC, HWW's right hand and the future Asmodeus), Corellon Larethian (also a PC) and some others.  Maybe Wee Jas.
Tiamat and Lolth will be there, but they do not fight.  This is why Tharizdun hates them.

I am going to let the battle play out.

I thought I would stat up all these gods in 5e and put them at 30th level.  Sure I could make them all 3rd level and the battle will be similar, but I want my players to feel like these are really powerful beings.
But I started thinking about D&D 5. It is great, but I have not done a lot of gaming at 20+ level with it.    So to add to the dream-like quality of it all AND to get the characters up to the 30+ level AND to have them be true immortals I am going to do something fun.

I am going to run this dream/flashback battle using D&D Basic.  Though OD&D is also on my mind.
The players know the rules, but they will be just off enough to make them have to think about what they are doing.  Plus looking down and seeing 31st level and over 100 hp will impress them.
It will also give me the chance to use some of my favorite B/X-BEMCI material.

Now I need to make some good looking "God" sheets and figure out who was there and who is going to play who.   Obviously if a character worships a god that is who they will be playing.

I have done this in the past, use a different system to invoke a different feel in the players.
When the dream is done each character will get a boon from that god to help them out later on.

The more I think about the more I like it.