HOW TO BUY: Buy all items left-to-right, top-to-bottom. "Laning" and "Core" items fill all slots (4/4/4) and "Flex" fills the first 2 flex slots. All of the other groupings with a * are options for the final 2 flex slots. Most games end without needing them.
HOW TO LANE: Play defensive. Use nades to heal self/lane partner. Use health advantage to keep light pressure up so you never get pushed back or killed.
HOW TO PLAY LATER: You're fully online at 8.5k. The playstyle never changes. Use ice bridge to rush to anyone that is currently in a fight or if you think one is coming. Use Rescue Beam to save someone (or just heal). Or throw a nade onto the enemy and icebeam to cut their movement/damage output and help win the fight. You can also help start fights with your speed/slow, but avoid 1v1. And I tend to save Ult for counter-ulting or trapping a high-priority target for teammates to kill. The strategy never really changes as you get more souls, you just get faster with better debuffs. Your beam damage endgame can also be quite strong if the enemy isn't leaning into Spirit Resist.