As I said before, this Item will never work. For example: at r7, where I am, most ppl have around 200 or 150 regen and 400 to 500 cap. Now if that regen were to suddenly go down by 90 so to around 100 or 50, it would be too op.
At r1, people have 400 or 350 regen with 500 or 600 cap, or they have 800 cap and 250 or 300 regen. By the time you use your Ice Dagger, you r opponent uses 2 valiants, at which point he has lost 100 regen and 90 energy (which he regens) and you have lost 480 energy, with drone, you are either broken, or down to 300 energy, with little regen anyways, so even excluding regen, you will be behind a turn, and the so called yo-yo effect will make you lose.
Energy v Energy nowadays is just whoever goes first, and has overall better en stats wins, if you go second, and you two have similar en stats, you sometimes do not get to activate drone, because energy is too time sensitive to allow you to destroy regen, and then move on to depleting energy.
So, this weapon is overall shit unless it gets 90 regen damage, which makes it too op at lower ranks. So sorry, it sounded cool but is not possible.
My proposition, just thought of this: 47 regen damage, around 100 en damage, and 150 drain.
Sound good?