Ok as you may have realised up to now that mob names are coloured from "grey-blue-yellow-orange-purple".
For grinding purposes, Orange mobs are the best to kill as a result that they give the most xp, yellow is decent xp to kill,
blue is not enough xp, grey gives 1 xp, and you shuldn't try killing purple because it gives less than yellow xp and means
the target is a few levels above you.
From 51+ quests are no longer enough to level you, you need to grind, eg. Kill mobs for periods of times to accumulate xp
into the lvl. A new type of mob is introduced into the game at this level and they are the "Mutated". These mobs will not attack
you unless attacked first, they are silver crowns so they can be affected by abnormal statuses and can detect stealth.
Two different Mutated can be found in each map starting from Darkrane Forest-Ashwood-Basilica Giovannis:
Darkrane Forest: Mutated Cannibal Plants, Giant Mutated Croshu
Ashwood: Mutated Angler, Mutated Flame Croshu
Basilica Giovannis: Mutated Power Penza, Mutated Verit
Recommended Grinding and Levels:
Mutated Cannibal Plants turn Orange on lvl51, turn Yellow on lvl54 and turn Blue on lvl61.
Mutated Anglers turn Orange on lvl56, turn Yellow on lvl58 and turn Blue on lvl66.
Mutated Flame Croshu turn Orange on lvl59, turn Yellow on lvl62 and turn Blue on lvl69
Mutated Power Penza turn Orange on lvl65, turn Yellow on lvl68
Mutated Plants are recommended for lvling on for lvl51-55, Mutated Anglers until they turn yellow - then theres a choice between Mutated Plants/Anglers to get to 59.
Then you can either start on Mutated Flame Croshu or do Mutated Plants/Anglers.
Good spots for Mutated Cannibal Plants is the two plants surrounded by the Sanja at Lumber Mill, a good place to solo plants is the one at the right of Lake Kisia and the one at Woodcutters Path near the NPC.
Good spots for Mutated Anglers are the two outside the Shrine of High Castor, or the 3 on the path from the Shrine to Ashwood Post.
Good spots for Mutated Flame Croshu are theres a triangle of 3 south of Kynari Temple in the trenches. The 4 in the V shape between Ashwood Post and Kynari Temple.
The 2 close to each other south of the Shrine, near the akba and lower lvl Shidlan.
Mutated Cannibal Plants have less hp but hit harder than Mutated Anglers, Mutated Flame Croshu have a debuff that removes 1500 Physical Defence, and can hurt.
Every Mutated has an AOE with the exception of Mutated Cannibal Plants/Power Penza.
Mutated Cannibal Plants/Giant Mutated Croshu: Move Speed+2 Armour Crystal, Green Forest Accessory.
Mutated Anglers/Mutated Flame Croshu: Hit Rate+3 Accessory Crystal/Cool down-4% Weapon Crystal, Burning Forest Accessory.
Mutated Power Penza/Mutated Verit: (Physical Defence+137) Armour Crystal/Crit Rate+6 Weapon Crystal, Demon Hunter Accessory.
---The Accessory Sets consist of Ring, Earring/Bracelet, Necklace. You get 2 certain accessory drops per Mutated.
Alternate Levelling Method-More Purposeful Grinding
There is an NPC at Shrine of High Castor in Ashwood called <Poacher> Cort Rogozer, he has a Shop from which you can buy Contract Scrolls.
A Contract Scroll can be right-clicked to obtain 1 of 6 random quests, cost 8-9k gold to buy depending on tax.
These scrolls can be used from lvl51~60 and reward Exp/Gold. These quests include:
12 Red Eyeballs from Anglers at Lake Kisia: 45k Exp, 1k gold.
15 Kynari Feathers from Kynari at Salia Pond: 55k Exp, 25k gold.
10 Vesper Claws from Vesper in Ashwood: 45k Exp, 1k gold.
10 Obsidian Fragment from Diambus in Ashwood: 75k Exp, 15k gold.
20 Unknown Armour from Lazapa in Ashwood: 100k Exp, 25k gold.
10 Xylemia Hairpin from Xylemia in Ashwood: 100k Exp, 25k gold.
To save/make money while lvling, do all the quests that you buy.
To lvl fast but lose lots of money, keep abandoning the quests until you get the Xylemia Hairpins/Unknown Armours.