Here's the list of all ultimate spells in the game, in no particular order. You'll start off with a few spells but you'll unlock the remaining ones after defeating each of the bosses for the first time.
Shield - Generates a shield that renders you invulnerable for a certain period of time.
Max Level: Longer Duration
Bullet Onslaught - Shoots several bullets for a few seconds.
Max Level: Bullets become more powerful, homes in on target, and lasts longer
Slow - Slows down enemy actions (movements and attacks). When enemies are slowed down, your timing may be ruined especially when anticipating enemy attacks or shots so make the necessary adjustments in anticipating/predicting enemy movement.
Max Level: Larger area-of-effect, longer duration
Freeze - Freezes enemies for a few seconds. This does not cancel out the enemy action so be careful when freezing enemies in mid-attack since they can still finish their attack animation once they're thawed.
Max Level: Larger area-of-effect, longer duration
Flame - Incinerate enemies for a few seconds. Upon activation, enemies will suffer from fire-based, damage over time.
Max Level: Larger area-of-effect, longer duration
Lightning Bolt - Summon a lightning bolt in a specific spot to strike down enemies. Due to this spell's limited range, it's recommended to lure enemies in the area of effect then dashing out of the way as you call in the lightning bolts.
Max Level: Calls in more lightning bolts concentrated on the same area.
Storm - Creates multiple whirlwinds in your vicinity. Whirlwinds are created for a short interval of time. This is perfect for clearing areas quickly and recovering MP since the whirlwinds can also destroy nearby destructible objects.
Max Level: More whirlwinds are released per swing.
Speed Boost - Increases attack and movement speed for a certain period of time.
Max Level: Longer Duration
Sonic Wave - Pushes nearby enemies away. This spell doesn't damage enemies but can push them off ledges.
Max Level: Larger area-of-effect
Stun - Stuns enemies within the vicinity and renders them immobile for the duration of the spell. However, unlike Freeze, stunned enemies will only stay immobile as long as you don't hit them. To maximize the duration of stun, avoid hitting enemies that you're not prioritizing to attack.
Max Level: Larger area-of-effect, longer duration
Ninja - Quickly recover dash gauge for a certain period of time. This allows you to chain multiple dashes non-stop.
Max Level: Longer Duration
Meteor - Call in meteors from the sky, landing on random spots in the immediate area.
Max Level: More meteors are called in
Spiral Onslaught - Order Lore to spray bullets everywhere. Particularly devastating when deployed in the middle of an enemy mob or right under the bosses' noses.
Max Level: Longer duration and more concentrated spray
Rage - Increase damage for a certain period of time.
Max Level: Longer Duration
Destroyer - Destroy all flying bullets
Max Level: N/A
Ambush - Damage enemies by dashing.
Max Level: Longer Duration