Shards is brutal if you want all the girls. 1000 shards is hard enough. 1800 shards are required to get all three. It's just not mathematically possible without significant use of puddings and/or slayers. It's not THAT hard if your shard bonus is +5 or more, but even at +5, you still need 300 victories in 5 days. It's a tall order unless you grind a ton.
I'm torn on shards. On the one hand, I love that it's over so fast and I can move on with my life. On the other hand, it's stressful in the sense that if you miss a single day, you've pretty much boned yourself.