A solo build that has worked great for me in E5 scenarios with as low as 350 IP on dps setup.
This is a Hammer main build with shotgun, but this will probably work with other off weapons as well (using a powerful single target power ability). Having a hammer with high weapon power will greatly increase the efficiency of this setup. This is ideal for hammer main tanks if they build a dps set on the side for scens and share the same hammer in both setups.
Primary weapon: Hammer
Secondary weapon: Shotgun
Basic ability: Hammer / Ground Pound
Active 1: Hammer | Razor Shards
Active 2: Hammer | Seethe
Active 3: Hammer | Eruption
Active 4: Shotgun | Raging Shot OR Rocket Pod
Active 5: Hammer | Demolish
Passive 1: Hammer / Shatter
Passive 2: Hammer / Outrage
Passive 3: Hammer / Annihilate
Passive 4: Hammer / Obliterate
Passive 5: Hammer / Unbridled Wrath
When dealing with multiple targets you spam Razor Shards and try to use Eruption when enraged to massively boost the damage. Raging Shot is mostly used to help defeating the higher HP enemies and an alternative attack when you need to conserve your hammer energy. You should ideally never end up using your basic ability (Ground Pound).
When choosing Rocket Pod you end up using your shotgun more. Rocket Pod is generally more energy efficient when you are doing harder content. Raging Shot is better if you need more burst.
Seethe very often gives you that extra energy and rage needed to get the last part of the job done. This saves you a lot of time compared to slotting a self heal ability as energy fatigue is a very time consuming state to be in. Seethe can also be used earlier in a fight to apply the DoT effect from Razor Shards early (very powerful!) or to buy another high Demolish or Eruption hit. Then you have it back from cooldown earlier. This is more efficient than using Seethe only when you are empty of Hammer energy quite often.
In scenarios this build was created to burst down waves as fast as possible so you can get out of combat to regenerate health and energy for the next wave. This is also why no self healing is present. If you are slow killing a wave you just have to avoid engaging the new one. For boss killing you unload all energy and kite or hide until your energy is back.
Progression wise this is also a very efficient build for anyone who are hammer main and mainly focus on boosting their hammer weapon power.
Currently I run E5s easily with ~400 IP. This is with all epic level 1 crit and crit power glyphs and a mythic 35 hammer. In addition I have a separate talisman with a Thirst signet (only blue 20 so far) that triggers a 2100 heal on crits every 20 seconds. This is not strictly needed, but makes things a bit smoother.