3) Having different difficulties like easy, medium and hard (and maybe even further) with also increasing winning prizes could allow both the newer and veteran players to have just as much fun. Having a 'one size fits all' game mode can be difficult for newer players and boring for the older ones, adding the different difficulties could also allow better people to gain tokens and wins faster, assuming that the wins and tokens also increases with difficulty. Each difficulty could have different / more / stronger mobs depending on which one it is.
This reminds me a bit of something called "Tower of Oblivion" from a game I play on my phone.
In this tower, there are 650 levels that you have to beat in sequence.
Each time you beat a level, you unlock the next one where there are better rewards and harder enemies.
Every 5 levels there's an additional reward on top of the regular rewards.
An adaptation of this for the Ancient Trials could allow you to unlock higher and higher levels with harder difficulties and better rewards.
After beating a level, you could replay it for a lesser reward if you want to grind for buying something.
5) Having class upgrades that you could gain after playing for a certain amount of games with a certain class, or just by buying it with tokens could allow players who have played more to speed up their gameplay with better weaponry, armour, potions, etc. Each class could have its own upgrades and buffs and if whoever the hell can make all this happen is feeling extra adventerous, you could add different pathways in which you could upgrade the classes so that not every maxed out class could be same.
Since the levels get harder each time, you could also have permanent kit upgrades that allow you to keep progressing.
You would probably want these upgrades to be purchasable through the currency won after beating each level.
With this design, the Ancient Trials leaderboard could be changed to showing who has beaten the highest level so far, rather than the current who has won the most, which is heavily biased toward who can spam wins in the shortest amount of time.
That way, how much time you have to grind Trials has less of a bearing on how high up on the leaderboard you are.
Side note:
-Zulrah in the wither state on a regular basis will shoot at the ground under his feet instead of at you, hitting himself and leaving you protected as long as you dont jump, but this is probably because he shoots out of the lower part of his body.
If you get Zulrah trapped, as seen in the image below, the wither state literally cannot hit you unless you go try giving Zulrah a hug.