Vol'jin by Demolij

Vol'jin is a highly immobile support, with all of his abilities being delayed and slowing him down to cast, and he can only cast 1 ability at a time. This is offset by the fact that this grants him increased durability, and the abilities in question are pretty strong. Although he doesn't deal much damage at all he gets a lot of armor and has higher natural regen. He can be countered by stuns and silences but his abilities have low enough cooldowns and can simply be cast again to make it less of an issue.

Spirit's Blessing is a very funky passive, granting a massive 40 armor meaning with good ability timings can let you absorb far more damage than a ranged non-dps should. More importantly though is the ability to move while channeling, which means if you stay close you can walk around while channeling a Tribute! It's an impressively versatile passive and is only gimped by you having reduced movement speed. It's also the reason his kit works at all, because when he has such strong abilities they need to be limited by the channel time.

Transfusion is your only heal and the skill you will use most of all. It's on a short delay so saving allies from burst will be hard, but the heal is pretty strong and has a really low cooldown, plus it gives you armor as well so use it whenever you possibly can. Hex is a devastating disable with a shorter wind-up, but a 2 second disable is a crazy long time. Bear in mind that both of you can move and neither of you can attack, and they are not slowed so they can get away, plus you can be interrupted just fine so it's not a win-everything move. It's still extremely effective against highly mobile opponents and can shut down carries super hard. Empowerment is one of your most impactful abilities in your kit being a cleanse at level 1. It has a measly 15 second cooldown giving it uptime multiple times during a fight, but it's strongly balanced by the 1 second delay forcing you to either pre-cast or land it late.

Big Bad Voodoo doesn't have a huge radius but can absorb heavy bursts of damage if timed well. It's pretty easily interrupted however, so take good advantage of the short cooldown and duration. It's an effective escape tool and is excellent against AoE at the very least. Voodoo Rip is literally your only damage spell, and can be a real pest to deal with. It suffers from diminishing returns against tank heroes and forces you to get lower health for it to work, which means you're more likely to die before the cast completes. Still, in the right circumstances it can be extremely effective (plus it can potentially save an allies' life).

When it comes to talents he actually has very limited healing options. On levels 1, 4, and 13, he has the option of picking up activateable Ward talents, which all utilize the same charge system. Each Ward can be picked up independently of the other talents, but each Ward you pick up after the first one adds an additional charge so you can have a maximum of 4 Wards at once, which gives you a good deal of flexibility if used cleverly. Raptor Tamer can give you uninterrupted rotations as long as you don't walk somewhere stupid. Lucid Focus cuts off about a second from most objectives or Hearthing, and can really throw enemies for a loop sometimes. Ancestral Ally lets you take other actions while disabling the enemy, with the trade-off that you don't get Spirit's Grace. Meanwhile Channeler is a funny ability that does nothing but give you armor and unstoppable, which can function similarly to a mobile Ice Block.