Firstly, being a p/s myself, i just wanna say a 3sec CD has destroyed the class. u dont see many p/s's anymore, ice blade was the most out standing feature of this priest combo. But in fairness it was a little over powered when people would exploit it and gear themselves up as a mage, focus on upgrading 1 ability and spam epic amounts of damage.
I think a CD is the right approach but 3 sec is too long, priests dont have many attack skills to rotate through, i often find myself using the scouts shot in goblin mines because im stuck with ice blade chain of light and frost scars and when frost scars doesnt kill a goblin and all my other abilities are in CD, i resort to shot to finish it off. i like the need now to diversify in combat, it makes playing p/s require more skill then just spamming 1 ability. but when it comes to instant cast skills priests are rather disadvantaged, and when it comes to PVP u often dont have the time for a 2 sec cast on your rising tide.
2 sec CD on ice blade would b fair enough with the same kinda damage
3 sec CD, maybe think about increasing the damage, as p/m get a similar ability but it deals more damage, and then on top of that, its 2 sets of it.
what if there was more emphasis on the scout side by dealing damage that could vary with ranged weapon damage like the s/m Ignite ability (if i understand that skill correctly) or maybe something similar to p/s rising tide, where there is a second set of damage dealt as ranged weapon dps
exhaustion effect: on spam-able ice blade i think is not viable because it would be too easy to eat up all your mana, then what? scout abilities?
using focus: yea could work but u would then still have p/s spamming the 1 skill
what if there was another attack skill added, it is traditionally known for being a dps combo, so if u rob it of its primary attack skill, maybe add something else to diversify with. What about making lvl 30 tide control additionally making shot a magical skill with a set CD, but that might be too much (was just a thought

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frost scars: fix it for the sake of all priests. My ice blade is lvl 63 it says it deals about 20% to 25% more points of water damage than frost scars, but when it comes to using these abilities frost scares deals less than half the damage of my ice blade, are the mechanics for frost scars wrong? maybe it should deal the kinda damage it says it does. and i think the same would go for frost death but i dont have that skill so i cant be sure.
Whatever the ultimate decision keep in mind it is the players who focus on the 1 spam-able ice blade that is the reason for all the hate over this combo, any damage reduction on the skill would not b fair to p/s players wanting to explore other playing styles for this combo.