Hello! I have been pretty much maining Skarner support and I was looking to talk about it and a few reasons I love it.
Disclaimer: I do not main a champ, rather I main spellbook and play around that + item actives and passives. I also only play normals as it's just more fun and that's why I play video games.
First one is I feel Skarner is a fantastic user of spellbook. There aren't really any bad spells on him (cleanse for surprise anti-lockdown when you engage/get engaged on, smite for e driveby objective/buff/camp steals, easy ignite and exhaust access, tp for roaming and flanks), and other than spellbook I don't think there are great support runes. Grasp and HoB feel inconsistent, Aftershock feels disappointing when you don't get to engage much and Glacial is bad with his E, and Guardian just feels less impactful. Been running Spellbook-Boots-Biscuits/Elixirs-Approach Velocity with Nimbus-Celerity minors and atk speed-move speed shards with the third depending on gameplan.
Another thing in the support role is that I kinda view him like Renata in that he mostly uses utility items as extra damage is expensive and he has great base spells as well as 4 cc moves. Bandlepipes, Knight's Vow, Warmogs, Locket, Mikaels, Protoplasm + others feel great playing as a secondary frontline, with easy to use passives on the character that help you focus on peeling with tons utiliy. Normally one or two utility items + Warmogs/Protoplasm feel great even if you aren't the strongest. Last season I was playing Celestial-Redemption rush and you felt tanky enough with huge heals and cc on every move (RIP Redemption health)
3rd reason is he kinda feels like crack to play. Yes he is clunky but honestly to me it plays into his character and hitting q3 is a fantastic feeling. Being a huge scorpion it doesn't feel like he should have quick/smooth options, only thing I wish is w felt more impactful but I do think it's an underated spell having a shield+slow+ a little poke on a low cooldown is really nice.
Lastly I don't think he has many awful matchups. Tanky frontlines are easily whittled down with q spam, engages are mitigated by great peel and you have surprising damage with q for turning engages around, enchanters are easily engaged upon. Only thing to me is mages as you poke less and can't peel + are a huge slow hitbox for them to hit.
This is my Skarner support post! Let me know if you play him and like different runes, or if you disagree with me, or if you think this is very cool very good. I really think Skarner support is underrated and is very viable in many situations. Thanks!
TLDR Skarner support cool