As an homage to classic tough-as-nails platformers like Mega Man, Mighty No 9 doesn't shy away from a challenge when it comes time for the final battle. This guide will walk you through the attack patterns of the last boss, so you can make it through alive and destroy the robotic threat once and for all.
The final boss of Mighty No 9 is Trinity, an out-of-control prototype that has been absorbing Xel like crazy. It comes in two forms: the first resembling a comet, and the second appearing like a flower. Both forms are mostly purple, and when weakened enough to absorb they turn a darker shade of purple. The difference can be subtle, so it may take a few tries to recognize when the enemy is vulnerable. As always, when Trinity is weakened you'll need to get fairly close with an AcXelerate dash to absorb the energy.
For both forms, the best weapon of choice is Battalion's Remote Cannon. It has a wide area of effect, it deals heavy damage, and best of all, it sticks to Trinity so you can plant a bomb and then trigger it later. This is particularly useful for the first "Comet" form.
Trinity v1 (Comet)
In this first form, the comet houses an outer shell that it sheds to form the projectiles for its attacks. Once it sheds about 60% of its total projectiles, it becomes vulnerable until it begins to absorb them back. You can use the Remote Cannon to latch a bomb onto the shell, and it will remain stuck on Trinity once she's shed her shell and become vulnerable. That means you can set up an attack during less tense moments, and focus on dodging attacks without worrying about aiming later.
To survive, you'll need to learn the telltale signs of each attack pattern and know how to avoid each one. In every case, in the Comet form, the giveaway is where Trinity floats toward.
First Attack (Bottom Corners): For her most common attack, Trinity will stay on ground level and fire projectiles toward you in a straight line, one by one, from the top to the bottom. You can remain standing for most of these and they'll pass right over your head. The only ones you need to worry about are the bottom two, but they come too fast to jump over them individually. Instead, jump-dash over both at once. Trinity will then pull the projectiles back to reform the shell, so just do the same in reverse.
Second Attack (Top Corners): Trinity will raise platforms and then fire projectiles downward as she moves from one side to another. If you're stuck on the ground level, you can't avoid taking damage. However, platforms rise as she begins the attack, so climb them quickly and dash-jump over her. If you stand on the side opposite where she floated, chances are decent you'll rise up on one of the platforms. As her life gets lower, this attack will change slightly, with the platforms falling more quickly.
Third Attack (Center): Trinity will float to the center, and staircase-like platforms will raise on both sides. Trinity's attack will go in a circular pattern, either clockwise or counter-clockwise, but it always begins in the 6 o'clock position. So simply wait on one of the sides until you can tell which direction it's headed, and then go the same direction to avoid damage.
Trinity v2 (Flower)
Unlike the Comet form, Trinity's Flower form is always vulnerable to attack and no longer encased in a protective shell. The head of the flower is the actual weak point, while the stem is usually an obstacle that needs to be dealt with in some way. And since she's no longer floating, the giveaway for the attack patterns this time will be a pixelated purple effect that shows where the plant will "grow" from.
First Attack (Bottom Corners): Trinity rises up from one corner of the floor and rushes toward you. Hit the stem with bombs 2-3 times quickly, so you can dash through and absorb them without taking damage. It will then turn and repeat, so keep doing that as necessary. Once the head hits the ground it will already have absorbed some damage from the blast radius of your attacks on the stem, and dash-jump over it to avoid its rushing attack.
Second Attack (Center): Trinity rises out of the center of the floor and fires its projectiles upward in arching spouts. This is very hard to avoid no matter where you are, unless you take out the stem parts quickly, which will leave the head low to the ground and unable to reach the upper platforms. Hit the stem hard as soon as it sprouts, then dash through and rush to high ground. Just wait there and leave it alone. You can damage it here but it's not really worth the risk.
Third Attack (Wall): In her most devastating attack, Trinity comes out of one of the walls and fires a large beam, first horizontally, then vertically. To avoid the first beam, stand on the second-furthest platform from where she appears, and jump up to the furthest when the beam grazes the bottom area. To avoid the vertical beam, stand on the same area and dash-jump as soon as it reaches the middle platform. The beam will turn off just long enough to get through. This is the toughest attack and does some significant damage, so don't be shy about using your Recover item if you're low on life, just in case you miss a dodge.