Well, that's the question I don't have an answer to. As of right now, I have D'Artagnan, Arthur, Solomon, and Joan of Arc unlocked.
Unlocking Shingen isn't going to happen anytime soon, seeing as how I would still need to unlock Masamune before that. Unless there's some other way to rustle up those holy points that I'm missing, I can maybe get around 100 or so per event
And yes, getting the regalias is relatively difficult since I don't play enough. Maybe 90 minutes each week? I started this past December.
Not to mention that I can't even remotely come close to killing the disasters. Perhaps it's my timezone but I've had very little success in finding assists for the lvl70 disaster kills