See in server folder MMTData and there check MMT_ItemDropRate.txt
Code:
//=================================================================================================================================
//Type Index Level Opt Luck Skill Dur Rate MonsterMinLvl MonsterMaxLvl Exc Ancient
//=================================================================================================================================
12 15 0 0 0 0 0 100 12 200 0 0 //Jewel of Chaos
14 13 0 0 0 0 0 130 25 200 0 0 //Jewel of Bless
14 14 0 0 0 0 0 126 30 200 0 0 //Jewel of Soul
14 16 0 0 0 0 0 350 72 200 0 0 //Jewel of Life
14 22 0 0 0 0 0 350 78 200 0 0 //Jewel of Creation
13 14 0 0 0 0 0 300 78 200 0 0 //Loch's Feather
Modify the Rate Tab there corresponding to loch feather of crest of monarch