Rakan question.

If he goes for regular auto attacks yes.

While unfortunately (or fortunately) he's counted as ranged, he can make good use of or.

Allows him and nearby allies to gain movement speed, making it a lot easier for to run around fights with his ult (don't forget about his ult's movement speed buff as well) and can also be used to help with his engages with his ult so he can use his W as a pretty much guaranteed hit on the targets he ults. With this item's quest, he also can improve a skill further to offer that little bonus.

Allows him to slow down enemies, but isn't as good in team fights with it's active. can use it when chasing down an enemy to slow them enough to where his W or ult can hit them so his allies can sweep in. Additionally, he can also use it to scout out for enemies to pick them off, as he can easily CC them to surprise them that can result in a kill or a flash. As a bonus to this option, his passive scales with AP so it offers a little more shield from that. Oh, and the quest gives him movement speed from hitting with his stacks.

By the way, it's important to note his passive is a shield that scales with AP that can activate even in teamfights, making it kind of like the quest achievement from the relic line.

Whats your point?

This is not a question xP

Each champion has items that are good or bad on them. For instance, you wouldn't build ardent censer on Kled, because he has no heals and can't make use of it. Relic on Rakan is similar in that he can't make use of any of its' early abilities. Thresh is the same way, except he's given a tool to last hit. If you want to play Rakan, then just build or depending on your playstyle. Judging by the fact that you want to be heavy engage, I'd say go for because the quest passive gives you a speed boost to add to your already absurd mobility and synergizes extremely well with your ultimate.