how powerful would noctis have been if he wasn't back injured

Noctis would likely have been more physically complete and probably more effective earlier in life , but the back injury would not necessarily change his peak “King of Light” potential all that much. In Final Fantasy XV , his real ceiling comes from his royal bloodline, the Ring of the Lucii, Armiger, and the power to wield the Royal Arms, not just raw athletic condition.

What the injury changes

The injury mainly affects his mobility and day-to-day physical conditioning, especially as a kid and during training. That means he would likely have had:

• Better stamina and movement.
• Faster mastery of swordplay and combat footwork.
• Less reliance on defensive or evasive styles.

It would probably make him stronger in practical combat sooner, because he could train and fight without that physical limitation.

What it probably does not change

The bigger part of Noctis’ power is supernatural, not purely bodily. Sources discussing his abilities emphasize his access to Royal Arms, elemental magic, the Ring of the Lucii, summons, and later the full inheritance of kings’ power. So even if he had never been injured, he still would not become a completely different character in terms of core lore power.

Most likely outcome

If he had not been back injured, the most reasonable take is:

1. He would have been a better-trained fighter earlier.
2. He would probably have had fewer physical limits in battle.
3. His ultimate power level would still be defined mostly by his destiny and inherited abilities.

So the clean answer is: he likely would have been noticeably more capable, but not drastically more powerful at his absolute peak.

In fandom terms, the injury feels like it shaped his fighting style and growth more than it defined his final power ceiling.

TL;DR: No injury = stronger mobility and earlier combat proficiency, but Noctis’ top-tier power still comes from his royal and magical inheritance, so his maximum lore strength would only change modestly.