felblade is the weakest talent choice in that row and doesn’t have synergy with any builds, I was thinking if felblade could have a chance to spawn a lesser soul fragment it might be a good option to take with feed the demon builds which lacks fury and soul generation.
Other suggestions
bake the current effect of razor spikes into feed the demon so that feed the demon is not a completely bland defensive talent option, E.G. new feed the demon reduces CD on demon spikes for every soul consumed and increases your physical damage while demon spikes is active.
maybe add a dot component to feast of souls?
i think soul rending at this point should just be replaced with something that can compete with the other options on that row, replace soul rending with redesigned talent gluttony.
Gluttony, consuming soul fragments now increase fury and increase your armor by % of your agility.
Also it would make more sense to swap demonic with ruinous bulwark, demonic is a stronger talent than bulwark and increases DPS while the rest of the talents on row 45 are not a DPS increase, similarly bulwark doesn’t increase DPS like the other talents on row 50.