Complex sentence: After InuYasha was able to break his barrier with the red Tetsusaiga, Naraku got injured by InuYasha and he almost beat him but he retreated to a mountain Hakurei-Zan for a long time, resurrecting the Shichinintai in the meantime to keep his enemies busy.
Split into simpler sentences: After InuYasha was able to break his barrier with the red Tetsusaiga, Naraku was injured by InuYasha. Thus, he retreated to a mountain Hakurei-Zan for a long time, resurrecting the Shichinintai in the meantime to keep his enemies busy.