Arcana Stat

I really like the way that Duskblade of Draktharr 's new passive works with Lethality as a stat.

The more items you have with Lethality, the stronger the passive effect is.

I think something like this could be used on some mage items.

Just for name sake, lets call this stat Arcana.

I'm always for introducing new items, and this could certainly be something that could be implemented on some new items as well, but just as an example, I would like to try and use this to illustrate my ideas of how this would work on a few existing items.

Firstly, I would use Liandry's Torment

The passive on Liandry's right now is static. It does not scale based on anything that you can do, other than impairing your enemy's movement. Even then, it has a diminishing return, which is okay, but doesn't feel very strong.

What if this % of current health damage were to be increased based on something, or at the very least give it a minimum damage?

My first thought was to have it scale based on something like AP, Level, Your health, MR, Magic Pen, .. something along those lines, but what if it were to adopt a similar scaling method as how Duskblade's passive scales on Lethality?

You give Liandry's and other items that it is 'encouraged' to be built with an Arcana stat that empowers the effect of it's passive.

This brings me to a second item, which I believe works rather well with Liandry's Torment, and I think has been a topic of note for balancing lately, Rylai's Crystal Scepter .

Similarly, the slow would be nerfed on base, and increased based on how much Arcana the player has received from other items. This would mean that this item would be weaker in many cases, but just as strong, or stronger when built in coordination with Liandry's or other items that offer the Arcana stat.