Disclaimer: This is a serious topic I shall keep as objective as possible, no trolling, with vanity left outdoors, no ego games whatsoever.
1. Who caused Edvard to leave SC? Who can take credits for it?
The main players: Me, Jim and Good helped by making it official. Though it would be fair to say I did the most. Before I came around, Jim, Good and Edvard were co-existing for years in harmony without me.
2. How have you caused that?
As you know, SC was facing issues in the past, err, pedophilia related ones, DDoS related ones, civil wars. I never DDoSed Luna's site at any point, so Jim can take full credits for the times it was taken offline by DDoSes.
To finally get to answering the 2. question, I did it by opening Edvard's eyes, in a metaphorical sense.
All the issues SC was facing made Edvard realize he was almost 40, and had been wasting years of his life taking an internet forum way too seriously.
Edvard came to this realization during the times he was banning Jim and my sock accounts, when Tor nodes were banned as result of IP banning sock accounts using Tor resulting in him not being able to visit SC, when SC was down due to DDoSes, and other times like that.
At least some of you must still remember how Edvard barely visited SC anymore even long before Luna deleted it and the database.
Edvard had found a better alternative to SC, I'm not saying he's found a different internet community to be part of, but rather outside the internet he's finally found something interesting to do with his 1/3 remaining life-time.
3. How has Good helped?
Good helped by banning Primal.
Edvard didn't enjoy SC anymore, and was in need of an excuse to opt out of SC while preserving his ego.
General Sun Tzu has taught us :
Build your opponent a golden bridge to retreat across.
Had Good not 'built a golden bridge for Edvard to retreat across', Edvard would still come around today sometimes, but very, very rarely, like Legga, but more rare.
This is the part where Good helped and made Edvard's leaving official.