Rakan Q feels really short and misplaced on his kit
I don't exactly understand the role this skill suppose to have on his kit. Feels more like an skill a top laner would have than a support.
Points I felt frustrated about: Upgrading it don't increase heal Range feels really bad High cooldown / strange synergy( could be lower if you land W or something like that).
Also, I really don't feel it's a necessary skill on his kit at all.
It kind is designed to avoid him having a weak spot being harassed( as you should self heal), and then have a low range to avoid win against people that harass ( what defeat the purpose of the skill).
This Is my suggestion: put the healing circle thing on his w if you land it and make this Q throw some feather like xayah that slow that xayah can also pull.
I think it would make more sense like that.
Or just give him an AOE slow like gálio.