Let's look again at the verse for context, shall we?
In Isaiah 45:7,
What is the opposite of Light?
Darkness. This sets a standard for the verse. It is showing us a comparison between the opposites of things that God created.
Now, another part of the verse says, "I make peace,"
What is the opposite of peace?
It's war or calamity or misfortune. Something that is the exact polar opposite of peace. Yet, you are going against the standard of what the verse says and are ignoring that words change with the passage of time in this instance.
Yet, for some strange reason you acknowledged that words change with the passage of time. So if this is true, then you at least owe it to yourself to look at the word "evil" at an online Etymology dictionary to see what it says.
http://www.etymonline.com/index.php?term=evil&allowed_in_frame=0
or maybe look at the online KJV dictionary for this word,
http://av1611.com/kjbp/kjv-dictionary/evil.html
or maybe look at the dictionary for this word,
http://dictionary.reference.com/browse/evil?s=t
or maybe look at a Bible concordance,
http://www.blueletterbible.org/lang/Lexicon/Lexicon.cfm?strongs=H7451&t=KJV
or maybe look at some other translations for the verse,
http://biblehub.com/isaiah/45-7.htm
Or maybe do a cross references search on Isaiah 45:7,
http://www.openbible.info/labs/cross-references/
or maybe you should read some commentaries on this verse?
Why do I say this? Because it will all lead you to the same conclusion that the word "evil" in Isaiah 45:7 is not speaking of evil in the moral sense but in a natural way as in meaning misfortune or calamity.
For God is not the author of confusion. He wants you to think logically and to understand Him. Does it make sense that God can directly create moral evil and yet it does not magically make him evil somehow? Can you create evil things and still be good? Can you explain that? Can you demonstrate a real world example of how you can create evil and yet still be good? I would like to know how that works.