I’m sure many of us mostly focus on leveling our legendary (5*) heroes and 4* troops which restricts us from doing Novice and Intermediate levels of Trial quests as those are restricted to 3* and 4* heroes.
My suggestion is to allow 5* heroes in Novice and Intermediate Challenge quest line by adding a penalty - an undispellable debuff to the attacking team that reduces damage done by X percent and perhaps also reduces the damage of offensive special attacks. This penalty would enable players to use their favorite heroes without them being too powerful, i.e only as powerful as 3* or 4* heroes.
In regards to items, perhaps something similar can be done as well.
What do you think?