I'm guessing you didn't even read anything.
Let's start with passive. It gives him the ability as well as makes it useful for him to roam and help out the entire team instead of just playing babysitter for the ADC. There are many other supports that would make good roamers too, but they lose out on experience when they roam, meaning that is is entirely situational and you HAVE to make something worthwhile come of it if you do. His passive gives him experience which is to make up from being away from the lane and a movement speed boost which is to help you travel from lane to lane faster--as well as mana so that when you help out a lane you have enough mana from traveling to the next to still help them out.
As for his Q, while it shares similarities to Lulu it can 1.) Only hit 2 targets at max, including a minion. Lulu's applies a very strong slow(80%) to everything hit. His has a much weaker slow, but that's because it can also STUN targets if you aim it correctly. It becomes extremely more useful when in the jungle/dragon pit/baron pit for the close quarter combat that will allow you to get stuns off. It allows him to, as a roaming support, say, come from behind the enemy and set up a kill for let's say mid lane by stunning the enemy against a minion.
His W is a health shrine. It is literally nothing like Soraka's heal whatsoever. To say that is like saying that Sona's heal is like Soraka's heal. Namely, it creates a shrine that your ally must WALK OVER to get the health--but it also provides utility in the form of movement speed. It doesn't spawn at max capacity, either, so it has to be charged up to reach its full power. This means that you're generally going to be sacrificing your positioning to regain your health. It can also easily be destroyed by enemies who walk over it, rendering it completely use it. Imagine though Bard roams to mid lane and drops a few shrines off under your turret so that the mid laner can just regain health without being forced to b. Or if the enemy jungler comes in for a gank they can step on a shrine to gain health and a bit movement speed to avoid/survive the gank. It's extremely useful and literally nothing like any other healing based ability in the game AT ALL.
His E is not like Reksai's tunnel at all except for in the fact that it moves you from one location to another--which is what every mobility move does. That being said, it is also a ONE WAY type of move and cannot be used to go in the reverse direction. On top of this, whereas Rek'Sais tunnels can only be used by her, these "tunnels" can be used by ANYONE. They also disappear after a short while as opposed to Rek'Sais which have a lengthy timer on them unless they are destroyed by an enemy stepping on them. I think it's also a pretty useful thing in that you can help an ally escape with it. Yes, the enemy can follow you through--but all that will do is position them directly in front of a wall for you to land a stun with your Q which can then turn saving an ally into getting a kill.
As for his R, at a glance, yes it is Zhonya's for everyone. But it is noticeably more complex than that. It can be used to disable a turret and save an ally, or protect a low health ally from a skill they can't otherwise avoid(Karthus R, Jinx R, Ashe R, Draven R etc). But more importantly it can be used to deny objectives to enemies. They are about to get your tower? Freeze it and murder them. They are going to get dragon? Freeze it/them and take it while your team miraculously appeared from thin air thanks to your "tunnel" from the back of the dragon pit.
I really don't think you even read about this champion otherwise you'd see he is EXTREMELY useful and has VERY POTENT and GAME CHANGING abilities if used correctly.