5 on-hit items with Sunbeam being the star of the show. Death's toll/embrace is less damage than the other starters but enables Sunbeam easier and is pretty good health sustain throughout the game without getting owned by contagion until upgrading.
Ward chalice instead of T1 axe is an option depending on how you value ward chalice. Trading a slightly delayed first item for 660 health per back.
Swap if the enemy team isn't building a lot of health. Gives more health sustain, pen, and increased damage on SBB and Obow procs.
Swap if you need more single target DPS than AOE procs.
Swap if you're not able to auto enough to stack tyrfing to effectively improve DPS. The 20% pen to your autos(which is most of your damage even in yellow number builds) and attack speed is good plus the mana and mana sustain feels good with the sunbeam active cost.