If I use Meloetta ex's "Echoed Voice" attack three turns in a row, would I do 190 damage on the third turn?
No, the bonus damage doesn't keep stacking. It is only applied for each next turn, so you would do 30, 110, 110, etc.
Echoed Voice




x2
-20
Echoed VoiceDuring your next turn, this Pokémon's Echoed Voice attack does 60 more damage (before applying Weakness and Resistance).


Beak BlastFlip a coin. If heads, your opponent's Active Pokémon is now Burned.
If I use Meloetta ex's "Echoed Voice" attack three turns in a row, would I do 190 damage on the third turn?
No, the bonus damage doesn't keep stacking. It is only applied for each next turn, so you would do 30, 110, 110, etc.
If I use Seismitoad's "Echoed Voice" attack three turns in a row, would I do 320 damage on the third turn?
No, the bonus damage doesn't keep stacking. It is only applied for each next turn, so you would do 120, 220, 220, etc.