A Dragonknight can cast a cone AoE skill called "Engulfing Flames", dealing Flame damage overtime and causing affected enemies to take 10% more Flame damage dealt from ALL sources for the duration of the skill.
It serves as a very powerful group DPS buff.
While building my Magicka Warden, it became apparent that even though I had a class passive that increased Cold Damage by 6%, it still was nowhere near enough to ever justify slotting an Ice Staff to cast Blockade of Ice. Coincidentally Mag Wardens struggle right now in DPS too, so a change like this specifically targets them.
My suggestion is this: Allow the Warden to cast a debuff on enemies that increases Cold Damage done by 10%.
Here are some ways it could be accomplished:
• Add this debuff to Arctic Blast. Enemies who take Frost Damage from this skill recieve the debuff for 10 seconds
• Add this debuff to enemies standing in your Impaling Shards (+morphs) for 10 seconds
• Make part of a passive - whenever an enemy is damaged by Winter's Embrace skills, they recieve the debuff for 3 seconds or so
• Add this debuff to Swarm (+morphs) while an enemies is affected by the DoT
• Add this debuff to Wall of Elements when using an Ice Staff (not a good way to go about it since it would become universal).
That's all

Just seems like something that should be there...... Mag Warden DPS needs it.