"Time for Bear"

Gene: "yeah but its just because I love killing 15 year olds"

Dante: "no"

Cadenza: "it depends on the 15 year old"

Garroth: "what kind of question is this?"

Zane: "I'd pay good money for a 15 year old to kill my brothers"

Vylad: "yes"

What connects Zane and Garroth, the thing they both share is devotion.

Garroth is devoted to Aphmau, phoenix drop, the people he loves. His betrayal was a moment where he turned his back on those loyalties but I think despite that, Garroth at his best embodies this. Theres a reason that hes still loyal to aphmau in season 3 despite his (out of character) issues with her at the end of season 2. There's a reason Laurence says he would struggle to kill Zenix if the situation called for it, theres a reason he tells aphmau and laurance to not worry about him and be happy together in season 2. Garroth practices a sort of self sacrificing loyalty thats based on his ideals. He doesn't blindly follow Aphmau out of duty, he follows her because he believes in her, in what she stands for, in the world she wants to shape.

Zane is also devoted, in a much different way. Not to irene, liked he'd lead you to believe. Zane is performative. He doesn’t really care about irene or her followers, he sees the power of devotion as a means to an end, using the devotion of others to his advantage. But zane still is devoted. Not to power as you might initally think, but to his father. Zane so badly wants to step out of the shadow of his brothers and be worthy of his father, the lust for power, too, is a means to an end. Because if he just gets something powerful for Garte, something to prove his worth, then finally he'll be looked at instead of dismissed. Finally the one person whose approval he actually cares about will acknowledge him. Zanes devotion is blind. He doesn’t care what Garte does or how he is. He has tunnel vision, with everything narrowing down Gartes approval.

Esmund, as we can glean from the glimpse of backstory we get to see, may have embodied a combination of these two types of devotion. His love for irene warping his view. While garroth leans more towards loyalty, and zanes is how devotion can spiral into obsession, Edmund is somewhere in the middle and can lean either closer or further from either of his descendents depending on your interpretation. He too utilizes the devotion his fellow divine warriors in order to drive them to action with him against shad. Whether or not these actions were out of a sense of pure concern for irene or something more selfish we can't say, however I'm inclined to believe the answer is somewhere in the middle.