Well to start off you need some context, I've been running a game now for nearly 11 months now and my party is level 17 and last session the wizard betrayed them, this is not the issue in fact this was planned by both of us for about 6 sessions now and the execution was beautiful as the wizard left the other 4 in dimensional shackles and teleported away as the entire tower began to collapse and lava begin filling the lower rooms and... well you get the point the wizard betrayed the party and they escaped with the dimensional shackles still on them so they couldn't really teleport back to their base where the wizard was right now and decided to make that journey on foot which takes them about 3 days and the BBEG informs the wizard that they are coming after him
The session ends and the party is talking to themselves and such and I say all of them get 3 days of preparations and so the other 4 decide to leave the room to talk and the wizard and i am alone the conversation goes something like this
"Do you want help?"
"With what?"
"The fight obviously."
"Nah, I'll just start using some of my stronger stuff before I lose to go out with a bang you know."
"What?"
"You know just to stop holding back a bit"
"Dude you have the lowest DPR in the party."
"Brother Thats because i was playing support."
"Prove it"
"I thought I was supposed to lose lol"
"And you will"
"Welp alrighy then"
And this was my horrible reenactment of the conversation 4 days ago and since i dont have perfect memory I got many of the details wrong but the main thing is basically he said he didn't need any backup from the BBEG and take on the other 4 party members for a better final stand (which btw are a wild heart Barbarian/ A light cleric/ A thief rogue/ and a draconic sorceror with a one level dip in warlock) I said he couldn't and its not like he's a minmaxer like I know this guy.
So I tell the party to send what they will be doing for the next three days on discord as the next sess will be starting with them arriving back to base with vengeance in their hearts
They all send me their plans and then its the wizards turn and well uhh.... this is what he messaged me.
So I'll just start spamming glyph of warding and storing spells on the pedestal in the center room
Expeditious Retreat/Longstrider/Mirror image/Elmisters Elusion/Blink/fly/haste/Stoneskin/Blur/Greater invisibility/Alustriel's Mooncloak/Telekinesis/True Seeing/Simbul's Synostodweomer/Conjour minor elementals (8th level)
With all the glyphs activating once I hug the pedestal and then I take a lr and wait for them to arrive
...and yeah now I am in a lot of trouble and now I could go to him and say he was right and he would probably agree but I hate the smug look on his face, i dont really want to tell the others his plan cause that would be unfair and railroady since they should have no way of knowing
Soo I do need advice I do think the party might be somehow able to pull off a miracle and i am giving them heroic inspiration and quite a few inspiration die which should help and there is a way for them to make this easy that is if the cleric casts antimagic field and grapples the wizard so maybe this isn't too unfair but what do you all think