Hi again :D
I prefer getting Mejai's after I got some more reliable AP source (after archangel's).
Furthermore, you should know Rabadon's passive is unique, meaning the second Rabadon doesn't increase your AP by an additional 30%. If your aim is to get over 1k AP, you should get a Rabadon's Deathcap and 4 Archangel's staves. Although I'm not sure it's possible to get over 1k with Leblanc, I think it's only possible with Ryze because he gets 140(+30% extra from Rabadon's) extra AP from his ultimate.

The tear did get made into arch angels right after rylai's, take another look before commenting next time =/

Its not the best. You have two deathcaps, those arent needed. You get a tear of the goddess, and then dont make it into an archangels. Its also dependent on your stacks from your mejais.

Needs work, but nice try.