Abyssal Cry

lvl 60 Marauder, skill gem lvl 9, sharing Increased Duration and Blood Magic with Enduring Cry.

Mob movement doesn't seem to be slowed down at all. It' smost eveident in Daresso's Dream in the mini-arenas.

The damage isn't increased by spell damage, isn't it?

I am using Abyssal Cry with Static Strike .. I feel it's a great combination, don't know why exactly, maybe Static's explosions are getting a nice boost from it.
Anyway, it's fun to play.

Are passive and gem modifier affects not being shown in the tooltip a bug or intentional?

It's a fun skill, but AoE is too small, and CD is too high. Even with IAoE gem and investments into AoE nodes, you still cant rely upon it all the time, due to 4 seconds CD. And Rallying Cry actually does quite the same job - helps you to clear packs even faster. Rallying Cry is more reliable and dont need to be spammed as often.

Explosion AoE is too small. CD...is ok for me. The slow is quite useless that I can't even feel the difference. And the true problem is, why it didn't slow the attack/cast speed? I think it should be either slowing the attack/cast speed, or avoid reflect from all sources.

The cost goes up way too much from leveling for too little gain. I can accept the starting cost being 26 or whatever, but it eventually scales up to 56 at lvl 20 for very little extra use... the slow gets mildly stronger, that's it. The % on-death damage is the same, the AoE and duration don't increase, the slow just gets about 30-40% more potent for more than double the cost.

Honestly, I very much enjoy the skill, but it seems completely and utterly pointless to level it above 1. Maybe if the slow also applied to cast and attack speed it'd be worth leveling (movespeed slows aren't nearly good enough to be worth paying that much to increase, but attack and cast speed slows are), or maybe if it increased the area per level (of the shout and the explosions) or something, but as it stands now? It's staying at lvl 1 for me, always. And that leaves a lot to be desired from a design perspective.

Level 76 Shadow playing a Wild Strike build. Using Inc. AoE and Conc. Effect as supports on Abyssal Cry. The skill feels great to use offensively; it completely decimates a pack when I get surrounded. I can also use it defensively to run away and kite mobs that I can't tank. The scaling mana cost of Abyssal Cry was too high for me. I could only effectively sustain a level 1 gem. The default AoE radius of this skill feels okay, but a small increase would really make it shine. I find Abyssal Cry to be a great complement to any build that uses a skill limited in AoE.

I've tested this skill with my Righteous Fire Templar in an Acton's Nightmare Map just to see if it could cope with the resurrecting mobs: it simply could not. It turned out that the cooldown is too long and the AoE for the debuff is too small. The duration of the debuff is too short. Most of the skelly were resurrecting consistenly. If you consider the crazy mana cost and the fact that it shares its cooldown with the much more useful Enduring Cry, this skill is very disappointing and not well balanced IMO.