Cern Life Steal and Utility (Conquest)

I personally feel that rather when people take time to publish a build/guide, they will get better understanding not by looking at other builds that may be "better," but rather explaining the issues with their build so they can learn.

Resolution, I'll first display your full builds for easy reference:

Devo's path: Hunter's Blessing -> Warrior Tabi -> Devourer's Gauntlet -> Asi -> The Executioner -> Frostbound Hammer -> Fail-Not -> Deathbringer

Trans path: Transcendence (rush) -> Ninja Tabi -> Devourer's Gauntlet -> Asi -> Jotunn's Wrath -> Frostbound Hammer -> Fail-Not -> Ichaival

Now, it's not to say these builds cannot give you success, but these are fairly unconventional and there are some reasons why we probably wouldn't suggest building this way.

Devo's path first. Your start is just fine. Blessing to Tabi to Devo's, though I will say that with no attack speed steroid, Ninja Tabi is sort of the obvious choice to me, especially since the rest of the build doesn't get close to max AS.

But after Devo's, you go immediately into double-lifesteal. While some people do build both Devo's and Asi, it's not really needed that much in the earlier portions of a game. When they do pick up Asi, it's typically late, and it's to box better or to partially counter lots of anti-heal. I wouldn't suggest back-to-back lifesteal.

Exe is a core item and there's no complaints there. But after that, you move into Frostbound Hammer. If you value the slow (MS slow), you can just use your winter stance. If you like using other stances, you can just switch past a certain point...e.g. 3 hits in Autumn, then switch to Winter. If you're also valuing the AS slow for an advantage in boxing, or the health, I don't have anything there for you other than you already obviously know about Ichaival as it's listed late in your other build. But I typically wouldn't recommend Frost unless you're trolling. If you want a legitimately effective build, skip Frost.

Then you finish up with Fail & DB. I'm guessing you value higher use of skills, but Fail is just not a recommended item, especially for Cern, who is very much focused on basic attacks overall. DB as the 2nd crit item is fine, but you'd be better off going with either Rage or WD first. And honestly, if you're committed to crits, then you should start building them earlier. A typical crit build for Cern might be something like Devo's, Warrior/Ninja, WD, Exe, DB, PS, replace Tabi with whatever. Another would be Devo's, Ninja, Rage, Exe, DB, Ichaival or WD.

The Trans path has bigger issues, at least when considering standard build directions. You're skipping the blessing, which hurts your basic attack damage, to rush Trans. That's technically something you can do, so okay. But after Ninja, you're doing double-stacking, then double-lifesteal, moving into Jotunn's, Frost, Fail, and Ichaival. Double-stacking by getting Devo's after Trans is typically not recommended, though this can work if all you're doing is farming mid-game. But when you opt for Devo's, your AS potential suffers, which is why the normal path is Trans -> Ninja -> Asi. And again with double-stacking lifesteal...sorry, but don't recommend that at that stage of the game.

Jotunn's is for ability-based gods, and again, Cern is basic-attack, not ability. Yes, you can get some good effect from his 2's root and the ult's AOE, but you get 0 function out of his stance switching. This also ties into not suggesting Fail-Not. Again, skip Frost, and as you're also getting Ichaival, I'll say that building 1 crit item for 20% crit is just not anywhere near optimal for damage potential. When you build crit, you typically want to get at least 50% to make it mathematically more reliable.

And finally, in this build example, you don't have any decent pen. 10 flat pen from Jotunn's, and 15 from Asi, doesn't really cut it for later-game. If you focus on basics, it would be Exe...if you focus on abilities (which you shouldn't) it would be Titan's.

Trans builds typically go Blessing -> Trans -> Ninja -> Asi. From there, you can branch into crits or Qin's...but also of course with The Executioner in either case. A typical end of build after Asi would be Exe -> Qin's -> Titan's Bane or other item.

In any case, I get the concepts you want, but they're just not that viable at this point. Hope these explanations help.