Abyssal Scepter Improvements

I saw the new proposed Abyssal Scepter and I have some opinions about it. For those of you who don't know, here is the newly proposed Abyssal Scepter:

New Abyssal Scepter Item Cost: 2500 Recipe Cost: 815 +30 Ability Power +250 Health +60 Magic Resist

UNIQUE Passive: Every 4 seconds emanates a pulse dealing 80 (+5 per champion level) magic damage to nearby enemy champions and reduces their Magic Resist by 15% for 10 seconds (stacks up to 3 times, up to 45%).

Now builds out of amplifying tome+ruby crystal+null-magic mantle (negatron cloak)

I play tanky AP champions like etc Here's my proposed changes (bolded):

New Abyssal Scepter Item Cost: 2900 Recipe Cost: 565 **+40 **Ability Power **+300 **Health +60 Magic Resist

UNIQUE Active: (4 second cooldown) emanates a pulse dealing 80 (+5 per champion level) magic damage to nearby enemy champions and reduces their Magic Resist by 10 for 10 seconds (stacks up to 3 times, up to 30).

Now builds out of haunting guise + negatron cloak

Here's my reasoning:

1. It's clearly designed to be for frontline/tankyish champions. Tankyish champions have no business needing % magic penetration, so I changed it to flat magic pen. Flat magic pen is best against backline/squishy targets anyway, %pen is too powerful.
2. Haunting guise is a solid item with currently only one build path (into Liandry's). If you're going to have an item (Abyssal Scepter) with AP, HP, and magic pen then you might as well make it build out of Haunting Guise
3. 250 HP didn't make sense to me, just make it a nice round 300 so it matches the HP from Liandry's. Increased the item cost to compensate.
4. 30 AP isn't even as much as a and seemed to low for such an expensive item. Added 10 AP to make it feel worth it (otherwise why give ANY AP??). Increased the item cost to compensate.
5. Changed the passive to an active (same cooldown) that works more like a ; leave it at a 4-second cooldown because it's intended for tanks so the longer you survive in the fight the more use you can get out of it.

INb4 complaints: "You are biased because you play champs that would benefit from this" -No shit. " will be too strong" -Well, Cinderhulk was nerfed in 5.9 it now deals less than half the amount of damage it used to, so this helps make up for that. Also, relax. My proposed changes made it flat magic pen, not % magic pen.