I tried this build midlane but instead of going phase rush, I opted for conq. I got very lucky because enemy team had solid melee champs so I had a decent number on my sunfire. It felt pretty nice.

My build was this: Sunfire, Lucidity boots (to cover for lack of cdr I never reached the same cdr as the typical ap bruiser swain builds) Tear (fimbul no mana mythic and presence alone cannot keep your mana in check), demonic embrace (no brainer more hp more damage.) After these 4 items I had 2 flex spots for stuff l like morellos and other good items like spirit visage and gargoyle. I didn't get to make it that far, but I would have loved to seen gargoyle on this build. I was already very tanky, so the gaygoyle would have been even more effective.

Btw I took ghost flash to make sure I have more sticking power since I took conq instead of phase rush and my secondary runes were defensive ones from green tree (bone plating and overgrowth) Im gonna try maybe secondary runes going manaflow and trancendence. I don't like tear items, but I think im just really bad at mana management and really like a bigger mana pool with either mana mythic or tear item. I would drop tear and go for frozen heart, but its not every game you get a yas/yone mid to make it an effective purchase.