[Item Suggestion] Reworked Sanguine Blade? Or new item itself!

Looking at Serrated Dirk , I was thinking how the unique passive -

UNIQUE: After killing a unit, your next basic attack (on-hit) or single target ability deals +15 bonus damage.

was just lost when built into Maw or Youmuu's and how the passive has potential to be more.

So my idea is to build Serrated Dirk into a reworked Sanguine Blade (or a new item) which can be purchased on Summoner's Rift with these new components bringing a similar "High-Risk High-Reward" playstyle that "Sword Of The Occult" had.

This is my suggested concept,

Sanguine Blade

Stats +20 Attack Damage

Passive UNIQUE: +15 Armor Penetration UNIQUE: After killing an enemy champion, gains two stack of Blood Tribute (maximum 10 stacks). Each stack of Blood Tribute grants +10 Attack Damage and +1.5% Life Steal at the cost of 6 Armor and 6 Magic Resist for 10 seconds. Assists grant only one stack.

The idea of this is to make an item that is cost inefficient but when you reach 1-2 stacks by killing enemy champions, it achieves 100% cost efficiency, thus making a high risk in purchasing this item itself. Each stacks takes away your defenses in exchange for offensive stats making it less of a "Snowball Item", punishing players severely if they fail to use this item properly.

>>I HAVE NOT WRITTEN THE COST BECAUSE THE STATS ARE SUBJECT TO CHANGE, but the item must be 80-90% cost efficient and reaching a 100% on acquiring 1-2 stacks only.<<

With the removal of "Sword Of The Occult", this brings back the risky and fun yet punishing playstyle it had, that Mejai's Soulstealer has.

Please leave feedback on what you think about this idea and/or what changes can be done to it, I'd love to this this on the Rift someday.

PS- Definitely would build Sanguine Blade with Sanguine Garen skin.