Create a high-quality, ultra-detailed image of a robot Big Cannon Ogre standing on top of an Ancient Gear Tank, with a gradient from green to black. The Ogre should be a handsome, Frankenstein-like character holding a jagged scimitar. Incorporate correct, fancy proportions and symmetry. Draw inspiration from the styles of Ilya Kuvshinov, Katsuhiro Otomo, Magali Villeneuve, Artgerm, Jeremy Lipkin, Michael Garmash, and Rob Rey, as well as the aesthetic of Riot Games.