It really should be an active, honestly, because:
A) You can't used Zhonya's when under cc, and if you could, that'd be broken as all hell.
B) Maw just does it on its own, even when cc'd, and creates so much toxicity between the two.
- Make Maw only be allowed to trigger when not cc'd if you don't want it as an active, even. I'd rather have that than anything.
C) The AD roles already has so many damn defensive options... It's not even funny.
- Phantom Dancer - 12% reduced damage with attack speed and movement speed, along with crit chance, and even features a ghosting effect.
- Maw - Massive Shield with decent amount of MR and AD, along with Armor Penetration, Spell Vamp, Life Steal... All on one item!
- Sterak's - Massive Shield (THAT ALSO GOES OFF AUTOMATICALLY) with decent amount of HP AND AD.
- Merc Treads - Since there are no Armor Pen boots (yet), they get another defensive stat on their boots and... What's that? Tenacity? And Magic Resist on boots? Hell yes.
- Mercurial Scimitar - a Cleanse, Magic Resist, Life Steal, Movement Speed, and the ongoing trend of a ton of damage again?
- Death's Dance - 15% of damage is taken as a bleed instead, with high AD, Life Steal/Spell Vamp, and CDR.
- Black Cleaver (since it is being used on carries more than bruisers atm) - HP, % Armor Pen, AD, Movement Speed, and more CDR.
- Frozen Mallet - Health and AD, with a slow effect on top of it.
That list was meant to be small. Instead, I realized an enemy AD champion can reduce SO MUCH DAMAGE while still dealing a ton.
TOTAL:
100 Magic Resist
Two Shields
30% Tenacity
Cleanse
15% Damage Taken as a Bleed
12% Damage is Reduced from Last Target Hit
1300 HP
30% Armor Penetration
45 Movement Speed, 20/60 from Black Cleaver
25% Base AD Bonus
285 AD
...and so much more.
Now I understand those aren't the stats you'll get from those items, as there are 8 items there, but you can only buy 6. Either way, you can adapt in so many ways, while AP gets what? Zhonya's, Liandry's, Rylai's, Ninja Tabi, RoA, Hextech GLP, Abyssal (useless versus AD) and Zeke's.
Now that sounds like a lot, but when you think about it, those are all health items excluding 3 of them, which offer low defensive stats anyways aside from Abyssal... Except Abyssal is worthless when facing AD.