Need suggestions for a Gnomeregan oneshot

Not sure if this is the right tag but here we go...

We're in the middle of a Forgotten Realms campaign and one of my players is on vacation for a couple weeks. So we decided to run a few Warcraft inspired oneshots while they're gone rather than progress with the main campaign. None of the players know anything about Warcraft except me. And since I'm going to be running a Warcraft campaign with them after this one wraps up, I thought it would be fun to get some background.

So the three one shots were based off the premise of the Caverns of Time and Nozdormu sending players to stop the Infinite Dragonflight from screwing up things in the past.

The first one was basically the end of the Last Guardian. Lothar and Khadgar are engaged in battle with Medivh and Garona is running to escape the tower to eventually go assassinate the king. The Infinite Dragonflight is trying to kill her first. So it was a chase sequence mixed with a defend the NPC fight.

The second one was when Fenris, Tagar, and Ragnok were sent to retrieve the Scepter of Sargeras for Ner'zhul. The dragonflight tried to sap their powers so that the demon guardian could kill them. The players basically had to kill the Dragonflight enemies before the demon could kill the NPCs.

The last one I'm planning is the opposite situation. The dragonflight is trying to prevent the destruction of Gnomeragan. I'm going to have the players appear in a control room where the dragonflight is defending a control panel to set off the radiation bomb. I'm looking for suggestions of spells or homebrew mechanics that would allow several creatures to prevent the players from just walking up and pressing the button.

For one, I think I will have it take more than one player to press the buttons. Like there are two different buttons as a fail safe. I'm considering it taking more than one round as in they have to maintain a sort of concentration on holding down the button (like a Con save when struck to keep their finger on the button). But I'm also trying to think of any specific spell or effects like a protective bubble that the dragonflight could cast over it. Perhaps multiple casters channeling a spell to put the console in a protective bubble?

Really just trying to brainstorm and thought I'd ask the community for help for this one. We're using 5.5e and the party is level 8. Thanks in advanced!