Alright, so here's how you can actually turn Earth Ally into an offensive weapon even though it's the weakest DPS contributor among the advanced allies (i.e., those with real runes). The first thing you need is a way to swap VIT for DEX. This can be either of the following:
1. A non-weapon, non-helm piece with one or two amethysts in place of emeralds
2. A high-VIT, medium-DEX piece that you can replace with a high-DEX, medium-VIT piece.
For purposes of this demonstration, I'm going to use my monk. I was running around with Eternal Ally a couple days ago, plus a pair of amethysts in my pants sockets. Here how my monk looked:
- Effective life (affixes): 551,935
- Effective life (melee, non-mantra spam): 1,100,196
- Effective DPS (not counting the ally): 242,626
So I switched to Earth Ally, which gives an extra 10% life (like any +X% Life affix). I felt my life pool was already in a good spot, so I started fiddling with the gems. Why not swap an amethyst for an emerald and see whether I'd get the same EL? Maybe even two. So, after switching two, here's what I had, given that I had just swapped 92 VIT for 92 DEX:
- Effective life (affixes): 548,641 (-3K and change, or -0.6%)
- Effective life (melee, non-mantra spam): 1,110,947 (+10K and change, or +1.0%)
- Effective DPS (not counting the ally): 252,781 (+10K and change, or +4.2%)
Not bad, right?
"Okay," you say, "but Eternal Ally does 60% of your weapon damage per swing, and Earth Ally only does 40% except for the special, which is 60% but has an 8-second countdown. So now what?"
Well, the good news about boosting my own DPS is that I boost the value of Earth Ally's swings. Here are the figures for both allies, after adjusting for the differing DEX values:
- Eternal Ally (60% damage per swing): 38,752
- Earth Ally (60% damage for one swing, followed by 40% damage for 11 swings): 28,037
Eternal Ally is still better, but it leads by less than it would if we didn't switch gems. The real picture emerges when you add these numbers to the monk's EDPS:
They're practically identical.
- Single-target EDPS with Eternal Ally: 281,378
- Single-target EDPS with Earth Ally: 280,828
But wait! As you add more targets, Earth Ally is worth more. Why? Because we boosted our own EDPS by nearly 5% when we switched the amethysts to emeralds. Also, you can spam Earth Ally for a constant 60% damage per swing, which gives it a decided edge over Eternal Ally.
Now, most players aren't going to consider Mystic Ally very seriously; even among those who do, Earth Ally would seem appealing only for pulling aggro and boosting your life (which probably makes it a good skill for ubers, if they'll attack the ally rather than you). But, with a little creative thinking, you can actually get a DPS boost out of this skill and still keep all the benefits, assuming you have some amethysts in your gear or some DPS-focused items you would love to try if not for the drop in life.
Fire Ally is still the best DPS winner, and Eternal Ally still has the singular advantage of never "winking out" for long when you're occupied with whatever elite pack is chewing scenery, but Earth Ally doesn't have
to be pigenholed into a "MOAR VIT AND LIFE" niche.