Sup! Translated from french by myself. Not a literal translation; I tried keeping the flow rather than going for exact words.
We know you've been waiting for a very long time, and that it isn't all that fun for you and for ourselves to have delayed this rework so much. As we've said before, we've had to do much testing, notably for Twitch, as the new stealth system poses problems between him and Evelynn, as he is ranged, and Evelynn melee.
Nevertheless, there are certain details which we are now certain to apply for the rework, and that we may therefore reveal.
First of all, Evelynn and Twitch won't use mana anymore, but rather, a "cold blood" bar which will fill up as you are stealthed, and will slowly drain when you are out of stealth and when you use your abilities. These will be effected by how much cold blood you possess. During the early game, we are aware that it may be hard to spend time stealthed, especially if you're busy farming your lane, or if you're jungling, which is why abilities will be stronger during the early game and therefore depend less upon cold blood.
The way cold blood will effect your skills is pretty simple. For Twitch's Expunge, your cold blood will allow you to ignore a percentage of your target's magic resistance (more or less, depending on how much cold blood you have), and so, inflict additionnal damage. For Evelynn, cold blood increases Hate Spike's range and the damage she deals. I ca't tell you these values exactly because we just aren't quite confident about the right numbers yet. I'm sure you understand that after so much time waiting for this rework, we wouldn't want to come up with something that players wouldn't enjoy.
We've also modified ultimate skills for both these characters so that they are more coherent with their new gameplay style. But, I may not give you any details regarding those, as they are still subject to changes.
Regarding the new stealth system, one of the main changes has to do with how you may detect stealthed champions. For this, we've modified Oracle. It no longer reveals neaby stealthed when consumed, but rather, possesses an active ability which allows you to reveal all stealthed enemies within an area equivalent to Clairvoyence's in size. The cooldown is fairly low, and the effect obvious, so that concerned players have a margin to position themselves properly and engage. Since Oracle now has an active and isn't really consumed anymore, we wanted to increase its price, but that prevented one from defending themselves with means other than Vision Wards. And so, we've had the idea of implementing a charge system. Upon purchase, Oracle has a precise number of charges, and once all of these charges have been exhausted, you must go return to base in order to recharge it.
We'll give you more info regarding the rework, but we may assure you that we're nearing our goal.
Thank you for your patience.
PS: Evelynn is getting her stun back upon breaking stealth.