Mighty No. 9
70 Achievements
1,000
Invincible No. 9
Complete the City stage without taking damage.
15
0.35%
How to unlock the Invincible No. 9 achievement in Mighty No. 9 - Definitive Guide
I did this in combination with Dynatron and Battalion's powers. Battalion's power is enough for mostly everyone since it usually weakens enemies for absorption and it also has a fairly large radius when it explodes. I used Dynatron's power if I felt unsure about an enemy but Battalion is enough for the most part.
As for the boss I used Battalion again instead of Brandish just to be safe and not take damage for being too close.
Using a mix of Battalion and Cryo and moving slowly you can get to the boss without getting hit pretty easily. The only tough part is when you are forced to fight waves of enemies but with Cryo it makes it reasonable. Use Brandish on the boss and just take him out. Some things that hit me on the boss:
When he does his dash move you will obviously jump over him. But if you are too close when he turns around he will hit you even though you don't get hit normally. I recommend staying away until he fully turns around.
When he shoots his 3 missile attack. You can destroy the first two missiles with sword swipes but I kept missing the third one. What I did was dash away when I saw him shooting the missiles. They then come at you in a line and are easier to destroy.