Although many knowledge graphs represent two views: (1) an ontology view for meta-level abstraction, and (2) an instance view for instance-level instantiation, Chapters 3-5 leverage merely instance view knowledge graphs for KG reasoning. In this chapter, we focus on the methods which incorporate additional information in the ontology view with the goal of further improving KG reasoning performance by jointly considering two-view KGs. It is important to note that both cross-view connections and intra-view structures in KG ontologies are essential for KG reasoning. We introduce JOIE [1] as the most representative work that effectively utilizes both pieces of information in a joint manner.