Original:  Zheng dynasts used the newly-owned island as part of the loyalist movement aiming to reclaim the mainland China from the Qing, mainly as a base of military operationsbut also deepening the process of Sinicization on Taiwan, in an effort to consolidate the last stronghold of Han Chinese resistance against the invading Manchus.
Revised:  Zheng dynasts used the newly-owned island as part of the loyalist movement aiming to reclaim the mainland China from the Qing, using the island as a base of military operationsbut also deepening the process of Sinicization on Taiwan, in an effort to consolidate the last stronghold of Han Chinese resistance against the invading Manchus.
Edit intent: meaning-changed