Serine/threonine-protein kinase component of the chromosomal passenger complex (CPC); a complex that acts as a key regulator of mitosis. The CPC complex has essential functions at the centromere in ensuring correct chromosome alignment and segregation and is required for chromatin-induced microtubule stabilization and spindle assembly. Involved in the bipolar attachment of spindle microtubules to kinetochores and is a key regulator for the onset of cytokinesis during mitosis. Required for central/midzone spindle assembly and cleavage furrow formation. Key component of the cytokinesis checkpoint; a process required to delay abscission to prevent both premature resolution of intercellular chromosome bridges and accumulation of DNA damage. Phosphorylates 'Ser-10' of histone H3 during mitosis. {ECO:0000269|PubMed:11350965; ECO:0000269|PubMed:12221116; ECO:0000269|PubMed:17199039}.