I will admit up front that I really don't understand the appeal of Atma's outside the old Atmogs craziness, so my analysis may suffer for that.

That said, I believe that the current mix of stats on Atma's, combined with the percent health damage boost make it very difficult to find situations in which it feels good to buy the item. The champions who get the most stats from the health-based damage don't necessarily need it (Mundo, Cho, Olaf maybe the exception), and the crit % is a bit weird since the champs who stack it (ADs primarily) don;t want Atmas, and the bruiser/jungler who wants a single crit item to blow up squishies is probably eyeing ghostblade.

The simplest solution to this problem is to convert the %health damage into flat damage to make Atmas feel better on low health targets. This would allow carries to grab it if they need armour in lane as a more expensive alternative to wriggles that would eventually grant them crit%. It would also make buying the item early seem more attractive as it would move closer to early lane items like phage and hexdrinker (even moreso if it got an armour + damage intermediate item). I recognize that armour + damage might be too sweet a combination to really allow.

Atma's gives Frozen Mallet damage at 2000 health, but it doesn't have anything like the same popularity as simpler defensive stat + damage options. Simplifying the item might make it easier to justify on a number of champions.

Atma's is certainly a niche item. however i think it works best on bruisers (surprise surprise)

it allows you to build tanky without sacrificing too much AD. a lot of bruisers can do ridiculous amounts of damage with only 200AD. with a frozen mallet, warmogs, Atmas, BV, and boots with furror (sp?) you can stick to any target and have the stats to survive pretty much anything they throw at you.

As an example:

Darius with warmogs, Frozen mallet, Atmas, BV, and ninja tabi. (last item is open, probably a last whisper or black cleaver would be best, but add stats as you please for the last item)

stats are 4200 health. 88hp/5. 153Ar and 103MR.

we'll have 206 base damage. base DPS would be 233.

burst from abilities over 5 seconds will be 2875.6.

with auto attacks he's doing 1165. for a total of 4040 damage. not to mention a good portion of this is true damage.

Let's compare this to blanc at the same price-point. (11860 gold)

Sorc boots, Deathcap, RoA, Rylai, Blasting wand, Tome.

She will have 2870 health. 83 DPS and 425 AP. so her offensive stat is over twice what darius has.

To make things more even i'm going to assume blanc has blue buff and enough cool down to get sigil off twice.

From abilities she'll have 3627.5 + 415 (AAs) damage. and this is assuming she'll get all her AAs off. unlike darius who will be AAing, leblanc may not constantly AAing. so we're really doing what we can to put this in the favor of blanc.

Her total burst comes to 4042.5

Now I do not consider Darius an assassin. by any means. he's a bruiser, and an executioner. however with his damage he's really more of a tank-assassin hybrid. which, IMO, is blatantly broken.

LeBlanc, i do consider a bruiser. so really at all stages of the game I feel like she should feel extremely powerful in a short time frame. 5 seconds is pretty short. and she can do considerable damage.

but when you look at bruisers, and the fact that they can pull off the same amount of damage, and be twice as tanky...

so no. I have to say that Atmas doesn't need any adjustments right now. if anything i'd nerf it. but it's really not needed. I feel the item is fine the way it is.

bruisers/AD really DO NOT need any better build options. they are fine the way the are and extremely versatile.

We could use a lot more build options for AP right now however.

Or u can just get sunfire cape and do essentially the same damage only with extra hp. Or better yet, 2 warmogs. lol

Most bruisers scale harder with armor pen and cdr than with pure AD and crit, for example Olaf is scary with armor pen and cdr but doesn't really need that much crit. Also, crit isn't a very valuable stat if you don't have and IE + the crit damage masteries.

Its really niche and almost never seen. It is silly to have crit on a bruiser item, most bruiser dont make use of crit the way ADCs do. Replacing it with pretty much anything else would make it significantly more attractive to health-stacking bruisers like olaf or mundo. Ad, ms, arpen, more armour, health, MR would all work.

Powerful on Garen, who can abuse the crit with his spin, and tends to benefit from tankiness. Garen's spin still scales with crit, right?

Yes, build Atma's on Garen and Olaf. I really can't think of anybody else who it really benefits.

Oh, gangplank. It works on gangplank as well, but most gankgplanks seem to prefer statikk shyv.