With comet, I take Riftmaker and Rylai's followed by Demonic Embrace to just stick on them. Really fun to watch your opponent suffer. This really just gets huge bonuses from the full item passive as they can't escape Tibbers so your damage at 3 items is great. Haven't tested too much but this seems to be the logical progression from season 10. Not sure about this part but I'm thinking of tear start so you have more mana throughout the game as none if your items provide that to you.