I would like to preface this with a disclaimer that I believe he was fine pre-nerf, and is acceptable at best post nerf. I wanted to present accurate data that I collected myself, and provide input and feedback. I tested against multiple units from each faction, the number next to their name indicates when tragedy kills them. Being that the baseline level for steel path is 101, if tragedy fails to kill a unit at that level with steel path modifiers on, I just mark down an X. Being that I am only mastery rank 28, the maximum level I can spawn is 195, so that is the upper limit for my testing purposes.
Grineer Test, just Tragedy 308% strength.
Butcher Reg - 195 / Butcher SP - X
ELancer Reg - 49 / ELancer Sp - X
Heavy G Reg - 34 / Heavy G SP - X
Bombard Reg - 24 / Bombard Sp - X
Grineer Test, Tragedy 308 + 2x Dark verse slash priming.
Butcher Reg - 195 / Butcher SP - 195
ELancer Reg - 195 / ELancer Sp - 195
Heavy G Reg - 195 / Heavy G SP - 195
Bombard Reg - 195 / Bombard Sp - 195
Corpus Test, just Tragedy 308% strength.
Anti-Moa Reg - 147 / Anti-Moa Sp - X
Moa Reg - 195 / Moa Sp - X
ECrewman Reg - 165 / ECrewman Sp - X
CorpTech Reg - 58 / CorpTech Sp - X
Notes: No staple corpus buffing/utility units were used, no shield ospreys, no nullifiers.
Corpus Test, Tragedy 308% + 2x Dark verse slash priming
Anti-Moa Reg - 195 / Anti-Moa Sp - 195
Moa Reg - 195 / Moa Sp - 195
ECrewman Reg - 195 / ECrewman Sp - 195
CorpTech Reg - 195 / CorpTech Sp - 120
Notes: Honestly surprised with how resilient corpus techs are.
Infested Test, just Tragedy 308% strength.
Charger Reg - 195 / Charger Sp - 134
AncientD Reg - 44 / AncientD Sp - X
Broodmother Reg - 58 / Broodmother Sp - X
Boiler Reg - 46 / Boiler Sp - X
Runner Reg - 195 / Runner Sp - X
Infested Test, Tragedy 308% + 2x Dark verse slash priming
Charger Reg - 195 / Charger Sp - 195
Ancient Reg - 195 / Ancient Sp - 195~* (varies by ancient)
Broodmother Reg - 195 / Broodmother Sp - 195~*
Boiler Reg - 195 / Boiler Sp - X
Runner Reg - 195 / Runner Sp - 195
Notes: About as expected, funnily enough the chargers almost died to dark verse alone. Regarding the ~*, these tests were especially inconsistent, with 11 enemies dying on average, and the rest taking little to no damage, this made it difficult to get an accurate reading.
Murmur Test, just Tragedy 308% strength.
Arcocanid Reg - 61 / Arcocanid Sp - X
Culverin Reg - 28 / Culverin Sp - X
HollowV Reg - 5 / HollowV Sp - X
Anatom Reg - 16 / Anatom Sp - X
LumberFr Reg - 12 / LumberFr Sp - X
Murmur Test, Tragedy 308% + 2x Dark verse slash priming
Arcocanid Reg - 195 / Arcocanid Sp - 195
Culverin Reg - 195 / Culverin Sp - 195
HollowV Reg - 49 / HollowV Sp - X
Anatom Reg - 63 / Anatom Sp - X
LumberFr Reg - 71 / LumberFr Sp - X
The addition of line of sight has drastically reduced the reliability of tragedy, its unprimed aoe potential does seem to be irresponsibly high versus the corpus and infested, but again my tests didn't employ buffing units that are common in their squad spawns. However, in higher level content, the unprimed aoe fails to function at a level that would be dominant, priming becomes a requirement.
With all of this in mind, heres some ideas that would be preferable as a nerf in place of line of sight.
Reduce the damage or damage multiplier of tragedy, and increase the damage and procs of dark verse. Maybe 2k slash damage base, and allow for the slash procs to scale with strength? maybe a hard limit of 2 slash procs per arm swipe? As for tragedy, 2 or 3k slash damage at base seems reasonable, and its multiplier could be reduced to 2/2.5
Now, before anyone mentions, yes I am aware he is able to kill level cap enemies when using roar, and stacking dots with viral. But the thing people seem to be forgetting is that they haven't nerfed his damage, they've kneecapped tragedy's reliability. Which is a far harsher nerf than any direct numbers reduction could been.