Wei-Min, as far as I can tell, only appears in the historical record to command the army which opposed the Mongols at the fortress of Kei-Min. Seemingly related to the Tangut royal family, he was intelligent enough to not repeat the mistakes of his predecessors at Wu-la-hai, avoiding open confrontation on the exposed plain against the Mongols. However, a false retreat tricked Wei-Min and he led his force out to attack the lagging Mongol rearguard, only to fall into Chinggis Khan's trap. Wei-Min was captured, Kei-Min surrendered and the way opened up for the Mongols to attack the Tangut capital. Wei-Min apparently disappears from the historical record, and it is probably a safe bet he didn't spend the rest of his days in a relaxing retirement. For more on Wei-Min, check out my video on the Mongol invasion of the Tangut Kingdom in 1209: https://www.youtube.com/watch?v=ScgDJUf6GVA