Hey all i was thinking about this idea quite awhile although i dont have names or the achievements yet or the rewards for each gotten achievement from players here's how it could look:
Finish all bio quest achievement:
"Master of inner spirit"
-free mall item
-some rare box or whatever
Also completing the achievement earns you the title also which can be equipped by the player and would show in the game like this:
so for example:
Master of Inner Spirit
Lv 1 LaceyMadskirt
So equipping this specific title gives you for example:
+200 Hp and +80 SP as long you have equipped the title
Dungeon completeion achievements
Ice run completed for the first time:
"Master of the Water Crystal"
Rewards same as all other higher lvl achievements depends on level of player
"Master Of The Water Crystal"
+5 or 10 % strength vs mob, +500 HP
Also completeing all other dungeons DT BlueDeath, Flame Run gives you same stats but different title name.
So anyways this was just example/idea how could look it doesnt mean i would want these kind of stats/rewards to appear in game but it could bring more fun stuff to metin 2 :).