Soooo... about Camille's true damage
I was testing Camille out in a custom game and... Yeah. That true damage...
At rank 5, her Q's second hit (if empowered) will convert 94% of the attack's damage into true damage. Note that this is not limited to the bonus damage from Q - this includes EVERYTHING that comes from the attack - sheen procs, crits, on-hit effects, etc.
So, I had Trinity Force, Infinity Edge, and Death's Dance, giving me 296 total AD. No other damage items. I was getting 2nd Q crits for just under 1300 TRUE DAMAGE. With 30% CDR (about a 3 second cooldown on Q). I could potentially do 1300 true damage every 4.5 seconds. Add in an Essence Reaver and a Bloodthirster, and you'll be crit'ing for 1800-1900 true damage.
Every 4.5 seconds. Why.
Now add in her % max health damage in her ult. Bye tanks! Seriously - a 4000 health tank will take 160 bonus damage each attack at rank 1, 320 at rank 3. Add the crit and convert to true damage, and they'll be taking up to 2500 true damage. In one attack. Plus, she'll already have attacked you a couple times for the first Q and an attack or two before the second. Sooooo... most tanks will be dead after 1.5 seconds of getting ulted.
Granted, she won't have much durability and that is only possible at the end of a game, but still...
