Now, you all already know that (Y/n) aka, you have three Quirks as you could tell in the USJ and hero Killer Arcs, right? But since I can tell there will be some doubts real soon, I'll list them all here while I'll stick to the main topic about ULTIMATE All for One

(Y/n) (L/n)'s Quirks [NOW]:

- ULTIMATE All for One

<Ability - ULTIMATE All For One doesn't just allows you to Steal & Give Quirks, it now allows you to copy their quirks permanently so you don't have to steal them unless necessary. Once there are quirks stockpiled and compatible with each other, they'll break down and fuse together to form new sets of stockpiled quirks.>

- Reionics

<Ability - Reionics is a quirk that allows you the use any kaiju, alien and robot from the showa to reiwa eras in the form of their body parts, their arsenals and/or their power. The Downside is that each kaiju, alien and robot has their own weaknesses.>

- Ultra

<Ability - Ultra is a quirk that allows you to use any Ultra from the showa to reiwa eras in the form of their forms they take or their power. The Downside is UNKNOWN.>

Now that's out of the way, let's go back to topic, shall we?

Now, in case anyone wonders what Quirks you have stockpiled inside your BRAND new & improved Quirk called; ULTIMATE All for One, here is a list down below on what Quirks you have, so far. 

New Quirks inside ULTIMATE All for One after Quirks were broken down and fused together:

ULTIMATE ALL For One
- One for All
- Quirk Erasure
- Hyper Regeneration
- Ultimate Combined Quirk Augmentation
- Vestroia
- Mutant Beast Transformation
- Transform Utility Creation
- Hyper imagination
- Weapons Utility Creation
- Supreme Teleportation
- CounterStriker
- Hyper Enhancer
- Hyper Duplication
- Hyper Sense
- Freedom Striker
- Sonic Doom
- Destruction Impact
- Nature's Wrath
- Gravity Control
- Reign of Darkness
- Reign of Light
- Turbo

Honestly, these sets of quirks suits you, really. Now, let's go through and see what all these fused quirks stated above are made of before and after theith original quirks broke down and fused together.

Now, the list of quirks that created your newly fused quirks are stated below.

Quirks that (Y/n) has in Possession & each Quirk that comprises of the fused Quirks stockpiled, & broken down inside to form New Super Quirks within ULTIMATE All for One:

- ULTIMATE All for One
1. All for One
2. Copy
3. Reactive Adaptation
4. Force Quirk Activation
5. Power Storage

- One for All
1. Gearshift
2. Fa Jin
3. Danger Sense
4. Black Whip
5. Smokescreen
6. Float
7. Superhuman Strength (All Might's Full Strength)

- Quirk Erasure
1. Quirk Nullifier
2. Anti-Quirk

- Hyper Regeneration
1. Super Regeneration
2. Ageing
3. Reanimation
4. Life Force

- Ultimate Combined Muscle Augmentation
1. Combined Muscle Augmentation
2. Muscle Augmentation
3. Body Bulk
4. Strength Enhancer (x4)
5. Power Quirk
6. Body Expansion Quirk
7. Body Morph
8. Juggernaut
9. Sugar Rush

- Vestroia
1. Elemental manipulation
2. Elemental Control
3. Air Cannon
4. Air Walk
5. Electricity-Powered Quirk
6. Burst
7. Liquification
8. Iron Fist
9. Titanium Claws
10. Flash & Thunderbolt
11. Metal Scales
12. Shadow Claws
13. Ice Claws
14. Fire Claws
15. Earth Claws
16. Metal Dragon
17. Vibranium
18. Metal Skeleton
19. Crystal Armour
20. Metal Teeth
21. Magma
22. Blood Manipulation
23. Dark Ball
24. Electric Manipulation
25. Sub-Zero
26. Bloodcurdle
27. Sonic Speed
28. Light & Dark Control
29. Time Control
30. Tree of Life
31. Metal Manipulation
32. Telekinesis Quirk
33. Mind Control Quirk
34. Levitation Quirk
35. Black Lightning Quirk
36. Vehicle Absorption
37. Radio Waves
38. Spatial Distortion Quirk
39. Camouflage
40. Naval Laser
41. Acid
42. Zero Gravity
43. Electrification
44. Dark Shadow
45. Half-Cold Half-Hot
46. Invisibility
47. Explosion
48. Weld
49. Twin Impact
50. Black
51. Solid Air
52. Hardening Quirk
53. Hardening
54. Steel
55. Poltergeist
56. Softening
57. Mushroom
58. Cemedine
59. Mind Manipulation
60. Fire Manipulation
61. Earth Manipulation
62. Ice Manipulation
63. Light Manipulation
64. Dark Manipulation
65. Water Manipulation
66. Liquid Manipulation
67. Gravity Manipulation
68. Space Manipulation
69. Air Wall

- Mutant Beast Transformation
1. Mole
2. Turtle Quirk
3. Wolf Quirk
4. Reptilian Transformation Quirk
5. Elephant Quirk
6. Brown Bear
7. Kraken
8. Megalodon
9. Crab (Alaskan King Crab)
10. Mantis Shrimp
11. Scorpion
12. Crocodile
13. Piranha
14. Armadillo
15. Lizard Tail Splitter
16. Beast

- Transform Utility Creation
1. Spearlike Bones
2. Spearlike Limbs
3. Rivet
4. Rivet Stab
5. Mouth Quirk
6. Hypertrophy
7. Transforming Arms
8. Multiplier
9. Body Appendages Quirk
10. Scalemail
11. Spike Shell Quirk
12. Wing-like Arms Quirk
13. Tongue Web
14. Wing Quirk
15. Ribcage Quirk
16. Giant Quirk
17. Feather Blades
18. Bone Manipulation
19. Bone Armour Quirk
20. Kaiju
21. Antannae Quirk
22. Hardening Quirk
23. Frog
24. Tail
25. Hardening
26. Dupli-Arms
27. Big Fist
28. Vines
29. Horn Cannon
30. Steel
31. Scales

- Hyper Imagination
1. Imaginary
2. Creation
3. Copy
4. Comic
5. Size

- Weapons Utility Creation
1. Imaginary
2. Razor Blade Quirk
3. Ooze Quirk
4. Glue Quirk
5. Transforming Arms
6. Cannon Quirk
7. Arm Scythe Quirk
8. Tool Arms
9. Shoulder-Mounted Jets
10. Helical Scythe
11. Sword Kill
12. Drill Quirk
13. Chainsaw Quirk
14. Chain Manipulation
15. Arm Blades
16. Bladed Fingers
17. Finger Blaster Quirk
18. Spike Enhancers (x10)
19. Sword Quirk
20. Free Bird
21. Fortress of Ultimate Absolute Defense
22. Feather Blades
23. Laser Fingers
24. Storage Quirk
25. Eye Beam Quirk
26. Tape
27. Pop Off
28. Creation
29. Gyrate
30. Razor Sharp
31. Cemedine
32. Bullet Lasers
33. Hydra

- Supreme Teleportation
1. Warping
2. Warpgate
3. Imaginary
4. Magiro Magica

- CounterStriker
1. Impact Recoil
2. Reflect
3. Absorption & Release
4. Shock Absorption
5. Blast
6. Rupture
7. Scatter
8. Air Wall

- Hyper Enhancer
1. Kinetic Booster (x4)
2. Brawn Boost (x3)
3. Speed Enhancer (x6)
4. Spike Enhancer (x10)
5. Hardshell
6. Subjugation Roar
7. Free Bird
8. Fortress of Ultimate Absolute Defense
9. Tree of Life
10. Magiro Magica
11. ET Booster
12. Primal berserker
13. Repulsion Quirk
14. Magnetic Manipulation
15. Strength Enhancer (x8)
16. Strength Booster (x5)
17. Speed Booster (x5)

- Hyper Duplication
1. Double
2. Cloning
3. Magiro Magica
4. Dupli-Arms
5. Multiplier
6. Body Morph

- Hyper Sense
1. Search (Ragdoll's Quirk) 
2. Infrared
3. Lie Detector Quirk
4. Vibration Detection Quirk
5. Scanning

- Freedom Striker
1. Flight Quirk
2. Free Bird
3. ET Booster
4. Repulsion Quirk
5. Engine

- Sonic Doom
1. Sonic Shriek
2. Earphone Jack
3. Anivoice

- Destruction Impact
1. Heavy Payload
2. Devastator
3. Explosion
4. Half-Cold Half-Hot
5. Blast
6. Scatter

- Nature's Wrath
1. Tree of Life
2. Mushroom
3. Vines

- Gravity Control
1. Gravity Manipulation
2. Space Manipulation
3. Zero Gravity
4. Spatial Distortion Quirk

- Reign of Darkness
1. Hydra
2. Dark Shadow
3. Black
4. Dark Manipulation
5. Shadow Claws
6. Dark Ball
7. Poltergeist
8. Light & Dark Control

- Reign of Light
1. Naval Laser
2. Light Manipulation
3. Invisibility
4. Camouflage
5. Light & Dark Control
6. Eye Beam

- Turbo
1. Sonic Speed
2. Engine
3. Free Bird
4. ET Booster
5. Kinetic Booster (x4)
6. Repulsion Quirk
7. Speed Enhancer (x6)
8. Speed Booster (x5)
9. Twin Impact
10. Sonic Speed

Interesting, am I right?

I know what you all might be thinking. How are Stain, Class 1-A and Class 1-B's quirks inside of you? And how the heck did you manage to grab One for All? Well, you see. Did you ever wonder why your Giga-Battlenizer has always been blinking? Well the answer is simple, your Reionics Quirk, the Giga-Battlenizer and All for One are resonating together and with each other, thus connecting the bond with both your quirks with it. In other words, once you have their quirk/s implemented onto your kaiju or alien, they will not just add as another arsenal in your troupe of Legion of Monsters, but it will also give you a copy of the specific quirk they took through any means (A/N: Means through blood, or by Adapting to their quirks as what were displayed by Ace Killer and IF.), adding another quirk to your stockpile of quirks.

And in case you ask how you'll return or give someone an extra quirk. Well, I have that covered. I don't want to spoil the fun so, you will just have to wait and see. The Search Quirk stated up above is already a "HUGE Hint" on how you'll be returning a quirk so, have fun figuring it out.

So, now that you know why and how your quirks work and what quirks created your newly fused quirks, LET'S GET DOWN TO THE HIDEOUT RAID ARC AKA, ALL FOR ONE ARC I, ya' Dig?!?!?!?!?!?!