It seems you need a total value of 530 for insta-cast.
How do you achieve this value of 530?
Each point in dex =2
Each point in int=1
The formula is dex*2+int=value needs to be 530.
So each and every increase to both stats benefit your casting time, dex does it more effectively but int also adds damage.
Let's say you have 120 dex/int.
That won't be enough because you'll only have a value of 360, you still need 170 extra?
How to get it?
Blessing adds 10 to int and dex stats, that means 30 extra on the value, only 140 left.
Job levels occasionally add stats, let's say a Warlock with max job level.
They get 11 extra int and 6 extra dex, that's another 23 points.
117 left!
We can use foods for both int and dex, but that's not accessible to all.
So, now we turn to equipment...
Since Clock Tower Manager Card reduces variable casting time by 5%, it would mean that that card alone adds 26.5 points.
91.5 points to go.
Since it's wise to use a 1handed staff, we can use shields, which will be an Orlean's Server in conjunction with 1 Orlean Glove, which adds 3dex = 6 points and 3% matk, always nice.
91,5 - 6 = 85,5
Due to the set, we can 10% reduction in casting time which equals 53 points.
So now we total in on only 33,5 points left.
We can attain this very easily by consuming 1 +20dex food, but let's keep it interesting.
We can simply buy a Survivor Wand at Lighthalzen, which adds 120matk and 2.
31,5 points till instant cast.
Or we can get a 4 slotted rod and fill it up with 3 drops and the above mentioned CTM card.
Adding another 3 dex.
25,5 left.
If you can get your hands on a Robe of Cast, you'll reduce another 3% of your casting time. [15,9]
9,6 left almost there!
Apple of Archer! Old friend! serving met with a nice dose of fresh +3dex since forever.
3,6 points left!
Hunt a Glove or a Orleans glove and we'll have reached our goal!
This is ONLY for variable casting times.
This means that some skills are not instant cast because of non-reducable casting times.
Other skills, however, do have variables only, meaning instant cast!
This guide is purely for reference and in no way a gearing guide towards Warlocks.
Int and Dex values for 3rd classes at job level 50.
Please note that this will only include characters who frequently cast something, so no Ranger's or Guillotine Cross's for example.
Warlock
Int + 11
Dex + 6
Sorcerer
Int + 10
Dex + 7
Genetic
Int + 11
Dex + 6
Shadow Stalker
Int + 5
Dex + 3
Royal Guard
Int + 9
Dex + 6
Arch Bishop
Int + 8
Dex + 6
Sura
Int + 4
Dex + 7