This idea is to give titles in the game more meaning to them and not just make them for show, as the game is right now when you get an achievement you also can show it off as a titles and achievements are gained mostly by doing something over and over again.
I suggest that all titles have stats on them which can ranges from 1 more HP point to even 5% life steal when they are equipped and harder to get titles will have better stats than easier to get ones.
Bat hunter (killing bats) Player does 5% more damage to bats
Wood cutter (cutting trees) Player drop rate for wood goes up
Out of the barrel (doing quest) Player gets 5% more exp and berries from quest
Like it Hot (killing fire boss) Player takes 5% less damage from fire attacks
That's just some examples on how it all can work and as you can see the titles also can fits what players get from them in some cases so when someone see a title like "Like it Hot" they know that player have a bit of resistance to fire attacks.
(P.S) That was the first part to my idea which is the main point of this post, this part is just an addon and does not need to be added to the first part but I think that the will bring more reason for players that have titles to want to keep farming that said mob or boss.
This part of my idea is to give titles ranks where players can upgrade their titles as they keep playing the game. As a player gets a title, they can keep doing what they did to get the title to upgrade the rank of that title and it will show with an outline of the rarity color.
Example with a title
Like it Hot
Common: Player takes 5% less damage from fire attacks (get 5o kills)
Uncommon: Player takes 6% less damage from fire attacks and does 1% more damage to fire users (get 15o kills)
Rare: Player takes 7% less damage from fire attacks and does 2% more damage to fire users (get 3oo kills)
Epic: Player takes 8% less damage from fire attacks and does 3% more damage to fire users (get 600 kills)
Legendary: Player takes 10% less damage from fire attacks and does 5% more damage to fire users (get 1ooo kills)
This part is to add uniqueness to not only player builds but also to titles because a player with a legendary title will have a bigger fear impact than one with a common title showing that one is a master at what they do apart from one that is a jack of all traits and just using it for that one fight.
This idea in a whole is to add uniqueness to players build, give max players reason to farm all types of mobs/bosses no matter what's the mob/boss level, Put a fear factor to titles and add more of an endgame to players that feel there is nothing left to do in the game.