You'll have noticed the "No more than nine wizards at a time" handwritten sign in the corner shop window. It's common knowledge that ten wizards together will inevitably brawl over some Ancient, Nexus, Titan, pick 'n' mix, or goodness knows what. Here's a secret: five wizards are just as unsafe, as they'll group up on an 'epic quest' and wander the neighbourhood to fight something, anything. 'PvE', they call it. A bloody nuisance, I say. Last night I found five steaming wizards tangled in my washing line shouting e.g. "It's casting Root!" and "Watch the adds!" while swatting at the peg bag.
Xing Tian's Mountain dunks five wizards on a magical mountain to fight waves of beefy enemies. Wizards start at level 13 with a fair chunk of cash, then must defeat each wave within a minute. From what I've seen, the waves cover a fair range of typical boss battles, like a damage-dealer paired with a healer, a biggun surrounded by a horde of mooks, a duo who get furious if their partner is killed, and so on. It has its own leaderboards, tracking the players who survive the longest.
This Smite wiki has a load more info on it all.
The mode will arrive in patch 3.17, which is due on Tuesday. If you really want a go now, you can hop onto the Public Test Server.
Here's a bit of someone playing Xing Tian's Mountain. I haven't checked the whole video but from what I watched he's a polite young man.