I was trying to come up with a oneshot build for the bow using the Snipe skill on Assailum and came across an interaction that seems like (on paper) it would be really strong. EA works by multiplying the explosion damage by the number of new EA arrows (up to 20) that the target is hit by after the first.

Many EA builds I've seen uses ballista totems to get to 20 stacks, but an issue with the build is that it is hard to know which EA is going to be the important one and which of the other 19 EA's damage values are basically inconsequential (and only matter because they are stacking the important one).

However, I feel that with Focused Ballista, you can now reliabily get some rather huge EA procs off. I plan on using Snipe, but even a regular 6L should still be able to do some huge burst damage (with a significant ignite proc after the fact) on a regular/semiregular basis. Here's how you would do it.

Firstly, 100% accuracy is kind of important here, because you can't afford your totems missing.

1. Drop 5 ballista totems with EA, Ballita sup, barrage sup, faster attacks and focused ballista (faster attacks is qol, multiple totems is easy way to get extra totems without investment). If using snipe you can use 6 totems if you want to guarantee you get 20 arrows to hit (if for some reason a few of the totem attacks miss), since you you'll only be attacking once with this build.
2. If using snipe, charge up the skill before releasing it at close to melee range. If self casting, go close to melee range and shoot one arrow (6L, just ramp it with as much more% dmg as you can find)
3. Once you let go of the attack, each of the 5 focused ballistas will shoot 4 (very weak) EA arrows as a barrage which (with minimal investment) should be able to all hit the target within the 1 second window that you need.
4. Rinse and repeat (if using snipe, you probably won't have to).

Obviously this setup won't work for mapping, but I have a slightly memey pob that can hit for 36 mil + 9 mil ignite without any expensive uniques (except bottled faith, which is a 20-25% dps diff, mostly because of the crit chance you lose). Obviously this build has very little in the way of defenses and requires a bit of a konami code to set up the full damage, but I'm not an expert with POB, and there's definitely a much more consistent build in there somewhere. For those who are interested, here's the POB: https://pastebin.com/391ecAHD. Ignore the full DPS number, it's completely busted. Just look at the Average Damage and Total Damage per ignite to figure out the true pop damage of the explosion.

I do plan on trying this out but I don't get that much time to play and I have another build I want to level first, so if I get around to playing this it'll take a good while to do so.