A just cause is invincible.

凡是正义的事业都是不可战胜的。

《新英汉大辞典》

He looked like a superman and seemed just as invincible.

他看上去像个超人，似乎是不可战胜的。

youdao

A redoubtable method, and one which, united with genius, rendered this gloomy athlete of the pugilism of war invincible for the space of fifteen years.

那种锐不可当的方法，加上他的天才，便使战场上的这位沉郁的挥拳好汉在十五年中所向披靡。

youdao

"It was an inexperienced, immature driver who felt that he was invincible, driving at night with a carload of kids.

VOA: special.2010.07.01

The foundation for another fine display for the seemingly invincible Super Falcons was a hat-trick from reigning African Footballer of the Year Perpetua Nkwocha.

BBC: SPORT | Football | African | Ghana and Nigeria reach AWC final

Case in point:Kmart, once a seemingly invincible retailer.

FORBES: Timebombs in the Vault

Regardless, Apple is quietly starting to look a little less invincible on the iTunes front, just as it is with the iPhone.

FORBES: Apple's iTunes Is Quietly Losing Some Of Its Luster