If I say

Another trait which she has would be that she is cunning.
Would this sentence still be present tense if I use "would be " in the sentence?

http://www.easypacelearning.com/images/tenses.jpg

It isn't present tense.

If you change "would be" to "is" then it'll be present tense.

No, the sentence "Another trait which she has would be that she is cunning" would not be considered present tense. The phrase "would be" is actually part of a conditional construction called the conditional future. In English grammar, the conditional future is used to indicate a hypothetical or possible future outcome in relation to a certain condition.

To determine the tense of a sentence, you should look at the main verb. In this case, the main verb is "is," which is in the present tense. However, the conditional introduction "would be" changes the overall meaning of the sentence, indicating a hypothetical situation rather than a statement of fact in the present tense.