Like Dusan said, you probably mean 1. He has become disgusting again, and 2. He became disgusting again (no "has" in the second one). They are similar in that they are both past tense but are not the same. The first one is used in more of a descriptive way, where the second is an event. In places where you can use the first one, you can often use the second, but not always the other way around. Examples: A: "What is he like now?" B: "He has become disgusting again." B is describing him as he is now. If B said "He became disgusting again", it is still correct, but that emphasises the event where he changed (not his present state). "When he rolled in the mud, he became disgusting again." This is describing events. 1 would be incorrect as part of this sentence because you're describing things that happened in the past. Rough rule of thumb: the first one describes something in the present that changed in the past, the second one tells an event from the past.

"Has" is being used as a present tense, while "became" is being used as a past tense. The two must be the same tense, so the first sentence is better. "Become" is also a present tense. :)

The second one is grammatically incorrect.If you delete the "has" in the second sentence, then it makes sense. I would use the first one.

is it little bit tricky?