Envy
Envy is a powerful demon from the Actraiser universe and a boss in Actraiser 2 where she has taken control of a former queen of Altheria and sank her castle, she is also seemingly behind the sinking of Tortoise Island: the reasons behind these actions are unclear but given the nature of Envy she most likely hated to see cities prosper so she destroyed them out of spite.
At any rate the Master can not tolerate her actions and sets out to vanquish the demon, unfortunately even the Master can not harm the floating head - which resembles a hideous hag and attacks with smaller disembodied heads: luckily he discovers her weak point is a flame that symbolises her own jealousy and once Envy is defeated the world of men is one step closer to being free of the demonic invasion.