Nice one, but few things:
1. You can still drain III Gin (at least in phase when darkness dont heal him). It will get partially resisted, but with Dark seal you should be able to drain 1-2k without magic burst and more with magic burst and be much more safe with 3-4k HP+
2. You should probably try at least darkness skillchain with Cata>Cata (3 step light could be too risky) like Logical showed in his video. Skillchain damage would be out of the roof with that base WS damage.
3. Small thing, but when you activate JA including SP abilities, use Soul Enslavement last. In video you used Meditate and Scarlet after Soul Enslavement and you basically wasted 6 out of 30 sec of its duration in JA delay (you started hitting when it was 23~24 sec left on SE). Also you can probably use it much earlier than at 10%. Probably around 24% and zerg it down easily ideally adding arcane crest and arcane circle.