I'll be honest, I don't really like the direction this is headed.
Tracking Device (new date.11/12) - added debuff so that it reduces targets Health regen by 50% while in effect.
Is just hanging back and sniping really the kind of playstyle you're seeking to buff? Isn't that pretty much the only thing most regulus players currently do?
It's already extremely effective, and especially if the other player doesn't have a monk, this will send them home way, way more than it does currently at low levels, and then at higher levels when HP inflates and priests hit the field just chain sniping people will only be marginally more effective than it currently is.
Think about this both way as a regulus player, what happens in a 3v3 with a reg on each side? They'll both have to sit back and practically crystal snipe to stay alive, and that's not fun for either party.
Mark of the Betrayer (new date.11/12) - While marked with the rune these following debuffs now apply: - attack rate slowed by 5/10/15% - Dmg output reduced by 15/30/45
Now this is a good kind of change. Reg needs tools to help him stand toe to toe with people later in the game, but I can see problems with having too many speed debuffs, as I note below.
Deadeye (Changed date.11/12) - removed stun effect - increased weapon proc rate to 15% - added a 5 sec debuff reducing targets health regen by 50% and attack speed by 30%
A level 15 skill like this is a much more fitting place for a major debuff like -50% health regen. I like the idea behind this. There's one problem that just occured to me though... Do attack speed debuffs stack, and is there a cap? Currently the way the game plays is early game autoattack damage is a pretty minor portion of total damage and it scales up to outrageous levels late game. Currently we have two characters who debuff it, but their debuffs are countered by artifacts pretty well (everyone gets about 15% haste just from leveling, and then you get another 50% or so from a few good artifacts, so you still swing at a good 120%'ish attack speed).
What happens if we add a third, fourth, or fifth attack speed debuff to the game? The likelihood of doubling up on those or even tripling up increases quite a bit, and that means the late game artifact scaling is thrown out of whack. People go from 120% attack speed to 60% attack speed, or possibly lower. As you can see I haven't really done any good math on it, but it's worth bearing in mind if we add more and more speed debuffs to the game, which isn't to say I disapprove of the ones here. Just bear in mind it's not an end-all solution and it might be worth exploring providing dodge or straight damage reduction somehow instead.
Also a lot of people are upset that everyone just HP stacks. If you further marginalize AA damage via stacking debuffs this problem only gets worse. Items like NR aren't even good when you've got a -70% attack speed debuff (assuming they stack).