Despite the being all about silence. All of Decibats attacks include sound cues. Although, only the third attack benefits from this
Weapon: Doesn't Matter
Armor: Doesn't Matter
Healing Items:Doesn't Matter
Don't move. It should really be a no-hit
Guaranteed No-Hit
Act > Watch
Circle around and you shouldn't get hit (hold X in case you reach the walls)
Guaranteed No-Hit
Act > Watch
The top corners are your friend. As they allow you to dodge the Blue attacks and gives you the leeway to get pass the Orange attacks
Start by going to the top left corner. Wait for the second sound effect and hold the arrow key opposite to the horizontal corner you are on (if you are on top-left, hold right. top-right, left). Repeat until attack ends
Easy No-Hit
Act > Watch
Head to the Bottom-Right (or left, doesn't matter) corner and wait until the attack ends. This usually ends as a no-hit, but there is a chance that a wave attack hits you
No-Hit. Small chance for a hit
Act > Watch. Mercy > Spare for Pacifist, Fight for Genocide/Neutral
Easy No-Hit. Small chance for a single hit