This skill is effective at dealing a constant amount of bonus damage to large groups of monsters in PvE, since it has a low energy cost and can recharge instantly. This makes it (as the name implies) well suited for farming.
If Farmer's Scythe hits more than one target, it ignores Diversion and still recharges instantly.
Bug! As long as Farmer's Scythe would have hit more than one target, it will recharge instantly - regardless of whether or not the attack actually hits anything. Thus it will still recharge instantly if the attack misses or is blocked.