Try out these runes lulu fans

summon aery ult hat transcendence gathering storm (flexible)

perfect timing (flexible) cosmic insight

Have ult up in on time at all via cosmic and ult hat. If in lane, max out on cdr and movespeed to be uncatchable and get extra ap for all that cdr beyond 40%. Or as support lulu. Even feel free to go tanky support lulu with stuff like frozen heart, redemption, or righteous glory. Scale up nicely via gathering storm regardless of if you build tank or ap.