Hopefully I can finally clear nightmare train before then, damn gargoyle shitfest!
It's done. Here's my tips for anyone who cares or struggled with it as much as I did:-
Equip A/S class health, attack, fire, ice, thunder on both chars (or best you have, elemental not needed as gargoyles don't use it). As soon as the stage starts, run past/through the first two to the opposite end of the train. Stay here right next to the minigun throughout, you'll knock some gargoyles off the train over the low walls and most waves spawn at the opposite end of the train so you won't pull them all at once and get swamped. Open the health crates when you get a second so its easy to grab the health quickly when you need it. Stay very close to alisa and try to gang up on the same garg as much as possible, this way she'll survive till the boss. Save the minigun for when devil jin shows up to thin out the horde. If you're quick/lucky you can kick or minigun devil jin right off the train for an instant clear.
With this strategy I can now clear this stage just about every other try. Stick it on hard and swap the thunder for a drop rate increase, you'll be drowning in S rank goodies in no time!