During your travels across Khitai, you may encounter the Scholars of Cheng-Ho. If you are frindly with them, you're not going to have problems. However, if you are allied with the Tamarin Tigers, you will have to fight them.
You may have noticed that they are usually accompanied by a pet called Moon Child. The Moon Child gives a buff to its master depending on the moon phase and this buff changes every few seconds. Here is a list of the buffs:
New Moon
Buff color: Blue
Effects: -20% to scale, magic damage and melee damage
Buff: it will grant 100% immunity so, if you are a caster do not attack when this buff is on as all your spells will fail
Crescent Moon
Buff Color: Red
Effects: -10% to scale, magic damage and melee damage
Buff: nothing major but make sure that you attack and kill the Moon Child first as it heals its master.
Half Moon
Buff Color: Green
Effects: None
Buffs: None
Waxing Moon
Buff Color: White
Effects: +10% to scale, magic damage and melee damage
Buffs: it will grant a buff that gives 10000 evasion. Needless to say, do not attack if you are melee since all your combos will miss
Full Moon
Buff Color: Yellow
Effects: +20% to scale, magic damage and melee damage
Buffs: no buffs per se but the Moon Child will attack you in melee and will fear you over and over. Annoying but could be dangerous if you are in the middle of their camp since you will run around feared and probably aggro other Scholars with other Moon Children.