Leviathan is in an interesting place for DPS. Most weapons tend to start strong and trail off as you keep firing mostly due to reload speeds. Xenophage for example (I ran on Kalli): On it's own, that first 13 shots is 22.8k DPS. After the reload you drop to 17.5k and now you're out of bullets. 26 shots within 15.6 seconds unbuffed. I think it holds 28, I accidentally saved the wrong damage clip and have to redo it. Leviathan's Breath held a steady 15.5k and slightly increased to 16k in that same amount of time and still had arrows leftover. 8 shots within 15.6 seconds, but you still have 7 more since it holds 15. So it could definitely use a buff, BUT, it also holds steady in longer DPS phases or if ammo is scarce. ...I have not yet done DPS testing with linear fusions yet (Just working on heavy exotics atm), so information still being gathered. As for "But what about X boss?" I find that damage tends to remain relative amongst same-class enemies. It might go up or down, but the Damage remains the same relative to each gun. For example: Templar takes 2.271x more damage than Kalli and it's consistent with every gun since Templar is also a Raid Boss enemy.