Lonely but steadfast

强调在孤独中保持坚定的信念或立场，例如：

*The scientist worked alone in the lab, lonely but steadfast in his research.*

Solitary and determined

突出独自行动且目标明确的特质，例如：

*She walked the marathon track solitary and determined, ignoring the crowds.*

Alone yet resolute

表示独自一人却意志坚决，例如：

*He stood alone yet resolute in his decision to protect the environment.*

Isolated but unwavering

强调与世隔绝却信念不移，例如：

*The lighthouse keeper lived in isolation but unwavering in his duty.*

Lonely yet firm

突出内心孤独但外在表现坚强，例如：

*Despite his loneliness, he remained firm in his principles.*

Solo but steadfast

表示独自行动且信念坚定，例如：

*The artist created masterpieces solo but steadfast in his vision.*

这些词语通过不同搭配精准表达了在孤独状态下仍保持坚定信念的复杂情感。