There can be a new NPC at some point in the game, a battle enthusiast, who the players can challenge daily and the NPC will have a random team of varying difficulty divided by reward (random day random reward)
Example to understand;
Day 1 :
A team of easy difficulty like Wilford's common team.
Reward for beating : (if possible let the player choose)
Option a) the location of a rare crit's spawn which is available that day, like - D.Flue at Palm trees in forest 2
Option b) (Harder to do for devs ) The spawn chance of a rare crit which spawns that day is increased for the day.
Like the chance of d.flue is now more.
The prompt from NPC won't be that, it vsn be
" I saw a dark flue today, i don't know where it went"
(user is told which crit after winning)
Day 2 : A difficult team with 4 legendaries and relics (or non relic, whichever devs find manageable) (maybe new hard bot) .
Reward for beating:
Similar to option A or B but it will be a legendary crit instead of a rare crit.
This difficulty and team of NPC can be randomized, or follow a cycle if the devs want.
This effectively adds a daily task with a palpable reward.
In case the player already had said crit, oh well, but with the number of crits increasing, it will be fair enough.

The location reveal tactic is a good way to make it engaging once the player base increases or when dealing with new areas.
The interaction between players who are creating and using guides will increase since the locations to crits will be found with eventual play and discussion of rewards amongst players ( this means that it might be better to have everyone receive random rewards for the NPC, and not the same for everyone).
since a big player base could end up finding all locations in a day. BUT not everyone will be on discord or follow guided right from the get go.
It takes time for new players to understand the possibility of the guides.