Try to get Kage, Philo Stone, and Heart of Gold first so you can earn money fast. Go straight to Abyssal scepter then Shurelya's and the rest is yours. Always use clairvoyance for scouting.
Using Rylai's scepter is a good way to delay your opponents during clash

What I love about this build is that you can also deal damage to your opponents while supporting your team mates. Try to be the 1st or last to enter. 1st so that you can silence quickly then move back or last so you can move around the battle field casting starfall while not being noticed. Use shurelya to escape or initiate clashes