It activates off of all critical strikes by any source and CD of the skill starts right after its procced so with the tiny bit of CDR i got the CD of the skill is 4.8 seconds for a duration of 5 seconds so it is up 100% of the time 
Warder added.
Unluckily, thatās not correct. After some testing in low level areas, itās clear that storm totem and wind devil do NOT proc deadly aim. 
Also, once it triggers (and I need to hit something with my weapon for this), thereās a skill recharge icon after deadly aim runs out and itās not possible to proc it during that recharge animation.
So, time for me to replace my groble sky effigy with a shield and hit things with my weaponā¦ 
Im mistaken in that and misread the icon sorry :D.
If you attach any devotion with weapon damage to one of the skills it should proc Deadly Aim.
Early levels i suggested Twin Fangs for that, im still contemplating in end game since the proc and heal is actually amazing and even more in Crucible.
I donāt wanna take away Ultos from Storm Totem since they match like butter and bread but Twin Fangs proc all the time when attached to ST and is a great source of sustainā¦
Thanks, thatās great news. 
Tested this and it works.
So, with twin fangsā and hand of ultosā weapon damage there should be enough triggers for deadly aim.
Interestingly, unlike storm totem and wind devil, the stormbox skill DOES proc daily aim. So, no need to go into melee range if I donāt want toā¦
Up to L56 using this build. Getting stronger with every level. I just facetanked the Warden on Elite. My health bar did not moveā¦
Hello, i am completly new to Grim Dawn and chose your build to start with, because its pretty well written for a new starter like me.
The only thing i canāt find is where to spend my attribute points on. Canāt read it out of the grimtools link.
Could you help me in this point?
You should invest everything into physique for as much HP and defensive ability as possible.
Not investing into Spirit makes us unable to equip high end caster off-hands but i already suggest leveling with a rare shield that offers bonuses useful to buildsās direction.
You can save up to 5-7 attribute points just in case starting from level 70s so in case you may not meet the requirements to equip suggested end game items which would only be the weapons in this case.
Overall spirit bonuses from gear and devotions should cover everything you might need.
What is your opinion on the Bardās Harp constellation? I have dropped Tempest instead and it feels a bit saver in HC.
I am not sure if the procc is really that great toughā¦
For proccing Tenacity of the Boar I am wondering if it would be good to use a 1H gun.
Savagery says it procs from default weapon attacks so using a gun would allow for staying out of melee range and could still have good things like % lightning damage on it.
I do not know if lightning gun weapons exist in the game.
Iāve thought about it and i liked the fact that without changing anything in the end game tree, it is possible to respec into both of them.
For non-Crucible, i might add it on the build since iāve tested it before and its a really solid choice but for Crucible i do like the chunky proc of Reckless Tempest too much to drop it and the OA/DA boost is good albeit not that necessary because the build has plenty of both anyways.
RT has pretty good damage and Electrocute ticks also quite well althogether and overall more damage and killing things faster are always good.
Storm Shard need 4 part of a purple set if I read the gear right.
That will be long time for me. What to bind to the Tempest devotion until I get it.
For early game melee weapon is not a necessity if you find any ranged weapon, a rare one with bonuses like Elemental/Lightning damage affixes preferred.
Proccing TotB in early stages shouldnāt be a concern for you and after a certain playtime enemies just charge to you directly and it doesnāt really matter whether you are melee or ranged, your tankiness is what matters at that point.
Anything that can crit will proc it such as Wendigo Totem or Inquisitor Seal or you can put a pointer in Rune of Hagarrad/Grasping Vines etc.
If you follow the devotion order i referenced, you would acquire Reckless Tempest around Ultimate difficulty anyways.
update: This build is getting more ridiculous with each level. L70 and cruising through bosses and MI +12 levels higher than me. In Malouth and about to do the Blackiron Docks. Currently all but two items are still L50. My suggestion to others who are following this build is to get the relic Eye of the Storm and to use the helm and shoulders from the Praetorian Set (+20% Damage Absorption).
I skipped most of the side quests in Elite to get to Malmouth so I can get revered with the resistance to buy the +100% XP potions.
Iām currently leveling using the Warden build posted earlier and it is working out very well. Thank you for taking the time to put this together, much appreciated.
Im glad you are enjoying the build and all the updates are valuable for me.
No problem at all, hope your gonna have a nice playthrough.
Pyroscar, what is the best legendary item farming route? I need to work on getting the Lights Guardian set, Judicators seals and eye of beronath. Fortunately, I already have a mythical Skybreach Bulwark and Mythical Spark of Ultos to work with.
Idk whether you are HC or not so make your choice according to that.
I think safes rogulike is Steps or Torment.
I also did good old Cronley + Hive runs for my first 2 characters before i dived into Crucible.
But now Rogulikeās seem to reward more and i started doing Roguelikes for fun and they do give me around 1-3 legendaries per run.
For my old farm routeā¦ If im not lazy i start from Foothils and enter Staunton Mine for boss and grab the Dynamite then to Old Arkovia, check for Boris then enter Hanneffy Mine from second enterance and coming out right back from the same exit i entered after boss and dynamite. Then check other champions spawns then porting to Cronley hideout. Should do a fast run (always spare Direni to farm him). After that i finish with porting to Twin Falls for clearing Hive then rinse repeat etcā¦
If you are lazy skip the Arkovian Foothills part.
Great build!
Added to my list of powerful AoM builds
http://www.grimdawn.com/forums/showthread.php?t=61983