Tbh,I think Reaver doesn’t need a buff.
Gotta hurry to solo Perilous before nerfhammer hits her.
Btw.
I still cannot decide should I take War horn or Roll.Both are so good.
Arrgh,decisions 
Reaver doesn't need a buff. Reaver needs the rampage glitch to be fixed.
With a decent weapon (~200~220 DPS) a Reaver can make it through threatening with ease using only 3 skills - Rampage-Dragon Rage-Devour. The 4th skill really doesn't matter and it comes down to the individual. Combat Roll, War Horn, Ring of Pain and Mighty Blow are all viable choices for the 4th slot. Yes, even mighty blow. Which skill you prefer in the 4th slot is up to you and the gear that you have. You can take Mighty Blow and Ring of Pain with zero opportunity costs, you must take them anyway. War Horn is only 1 point, but it is worth taking even if you aren't going to use so that you can take the Flow of Battle passive. Combat Roll has the greatest opportunity cost as it is worth 2 points if you want it to be truly effective and those are 2 points you can not spend on passives elsewhere.
Combat Roll - Evasion/defense move to keep you alive and remove status effects.
War Horn - Rampage has a 10 second duration and a 25.5 second cooldown. The CD begins at the beginning of the rampage cast so you actually only have a 15.5 second gap between when Rampage ends and when you can cast Rampage again. If you take the flow of battle passive you can get at most, about 8 criticals in the 10 second window of rampage and that lowers the cooldown of rampage to roughly 17.5 seconds. You now have a 7.5 second window you have to close before you can cast Rampage again. War Horn is best used immediately when Rampage goes away so that you can buy yourself 6 seconds of life to bridge the 1st Rampage to the 2nd Rampage.
Ring of Pain - Gives 50% damage boost to Dragon Rage + 15% weapon damage Dot. I use this skill to give me that extra hitting power so that I can clear out the mobs in my 1st cast of Rampage. Since acquiring a better weapon, the extra 50% damage to dragon rage isn't needed as much.. at least on threatening.
Mighty Blow - At first you might think this is absurd and doesn't fit, but some people might find it better off to have an offensive attack that can do damage while Rampage is on cool down instead of trying to manage Dragon Rage-Devour and their health bar during the Rampage cool down. This is for those people who don't want to Dragon Rage and bring their health down.
What you have to ask yourself is what skill better suits my needs considering my gear and my play style.