User blog comment:GutsyTick/Zamael/@comment-6719710-20150126094848/@comment-7709681-20150127002058

One of the problems between them is how each is targeted, how each scales and, most importantly, none is the main source of damage output of their kits (In Rek'Sai's case is her autoattacks, plus the bonus damage from Q).

Your ability is AoE and by no means should be able to retain such a low cooldown if it's to compare to Rek'Sai's E (Yours outscales hers) or Q (She is sustain damage, yours is burst damage).

Your ability, unlike hers, has a fixed base damage that scales by ranks, hers not only has no base damage on the ability but, also, due to the nature on her scales, has a linear increase per level thanks to her base AD, but that's it, she needs to build offensively in order to deal damage, your concept as a hole can go almost defensive and deal much more damage than she.