OK so I’ve gone back through the list of caps on pvp but are normal procs capped at all like if you have 60% proc chance I wanna make sure that that isn’t capped and you will actually have 60% proc chance on that skill (I know everytning is taken down too level 20 60% is just an example) also mana shild proc is a thing right? It’s not listed on the wiki and it’s been a while since I’ve played a while bunch so I can’t remember
No, mana shield isnt a proc and proc chances are still uncapped in arena i
believe however they dont do anything pas 100% but in arena you cant actually achieve 100%, for testing reasons i did some calculatioins and the highest i could get meteor was 80 something% so not enough, but sets are not nerfed however if you have the ‘all sets’ affix then this is nerfed and will affect your overall set count in arena
Just take a gander at Aftermath. 
Have a look at my build or the way my AI acts in eternal league. My build is a mastery of proc builds in arena and yes it is aftermath! I have earthshatter, storm, coat, stealth, bombard,fear and taunt as procs as well as meteor skill which doesn’t need a proc in my build. I like terrashaper but I might change it so aftermath 3 becomes 4 from 2 all sets affix (+1) . Also it takes into account elemental dmg, weapon dmg, ed% legend affix, blistering, stun immune just becz, bleed dmg and hp from vampiric touch and inferno to speed up dmg as well as increase fire dmg. If you tested my build, you can easily see why I do so well in eternal league. I also have vanish as proc but for demonstrate purposes, I just call it free 10% stealth proc. Also sureshot in my build to guarantee crit when full hp and coat to make sure more criticals. My build rrally deadly when it comes to critical and I even have two crit dmg cyan affixes becz of how good it is.
My build can do lot of dmg in second if alot land on opponent and sureshot helpd a lot. The best scenario I ever seen is having dealt 11k meteor dmg, 11k storm dmg, over 20k bleed dmg, 10k + fire dmg, 11k explosion dmg (aka bombard) and it all happen in a second sometimes. Also I have 2 all procs mythstone for total of 6% to increase proc chances immensely as well as energy mythic for a replenishable mana supply with the bonus % dmg and if full, I deal 100% extra meaning my dmg is doubled. This helpful all around. Also provided I have full energy or close,coat proc and stealth activating and then summoning meteor with procs, I deal deadly dmg. Biggest dmg I ever done iverall was 100k without a sweat and got to 165k without much effort either.
Defiant makes this all possible and that why I winning so much. I gt constant streaks of 7-10 at least and I have beat clogon a few times as well. Procs are very powerful if put to good use with concepts from builds like lohko which is what I based it on and they are the main reason why I got eternal league snd before arena came out, I played with aftermath and meteor procs which is what krpt me playin for months. I can never stop becz of the huge depth to it.