The two coordinate clauses, 'All....need' and 'there he ... .prevail' are in relative contrast. 'Yet' means 'nevertheless' which gives the desired meaning here. 'Although' is misplaced; it ought to figure at the beginning of the sentence for the right sense to be conveyed. 'Still' is very similar to 'yet' but 'he was there' is not as effective as 'there he was' in conveying the contrast. 'But' is ruled out as it conveys a stark contrast between two opposite ideas which is not the case, here.