The power I posses is the strongest in this world! The enemies I must defeat... are humans!?

I was Suddenly transported to another world. Being called the ‘Suitable One’, with the world’s strongest power “Holy Sword”. I thought I would be using that power to make a great impact in this new world. However, in this alternate world there are "inhumans"; Monsters that oppress the lands. Questioning my own convictions, I ask, is this correct? Who should I use this power for? This is the beginning of an Isekai battle fantasy!