@Riot Sion Passive Concept
I've been thinking for a while now about how underwhelming and out of place death surge is in Sion's kit, not only does it not make sense for someone who thematically is even stronger while dying but it simply doesn't belong on a tank. Why in gods name would you have an ability to give mobility on the guy who "With his dying breath, choked Jarvan I to death." With that said, I have come up with a far better concept that would thematically and from a gameplay perspective suit him in my opinion.
Passive: Glory in Death
Sion starts to bleed out rapidly, taking 5% of his health as true damage every half second and becoming immune to all forms of heals or shields. Sion gains 5 extra movement speed per 5% health missing and his basic attacks grant him 20% lifesteal. All of Sion's abilities are replaced with Final Stand.
Final Stand - Sion can target an enemy champion (and only an enemy champion) to lift them up and begin choking them. The duration of this effect lasts until Sion dies and the target takes 25 + 15% of Sion's base AD per second as physical damage and applying on hit effects every tick. While being choked, the target is suppressed and at the end of the effect they are slowed by 40% for 1.5 seconds. While Sion is using this ability it can be interrupted with silences, hard cc, and his bleeding increases to 10% every half second.
Please feel free to give me your feedback and I also would like to state that I believe this would be a great addition to help Sion after the nerfs that will be coming in the future. Thank you for reading and have a nice day!