Though he was rich (πλουσιος ων). Concessive present participle ων from ειμ, to be.

Be became poor (επτωχευσεν). Ingressive aorist active indicative of πτωχευω (see verse 2. Corinthians 8:2 on πτωχεια).

Through his poverty (τη εκεινου πτωχεια). Instrumental case, by means of.

Might become rich (πλουτησητε). Ingressive first aorist active subjunctive of πλουτεω, to be rich with ινα (that). See on Luke 1:53; 1. Corinthians 4:8.