How do I get rid of the Ctr (counter) stat?

It's not currently possible to get rid of or hide any stat. The best to can do is to blank out the name for any stats you don't want (which leaves a 0 visible), or perhaps use them to show something else, either another battle stat (like the base stat for a special class of attacks), or something unrelated to battles such as FF8's salaries.

The Ctr stat is often used as a temporary variable in battle, such as tracking a hero's rage, used as the best stat for special attacks. It will never be actually be given a special use like counter attacking (that might use a new stat)

Dorumagesu: You can use this stat for something like style or cool. It doesn't have to do with battle. Dragon Warrior 7 has a stat like that.

Abelhawk: Another possibility is simply using it to track the hero (or more useful, the enemy)'s level.