Harder monsters, higher health sure and yeah it's fun on my summoner when i notice i'm down to 1khp and the monster i'm fighting still has a bit left. However, to encourage people more these monsters and fates need to reward more exp.

Ultimately, 14k doesn't make a dent on 3million exp required, so not, i'm not going to waste my time on them, other than jumping into epic fates if they are up as i pass.