@Rover 'cause despite already losing twice she's so spiteful and full of herself she felt the need to boast about her powers. She wasn't aware of how much stronger they got and went at them thinking it'd be a for sure victory if she went all out regardless of if they knew or not since they wouldn't be able to deal with it anyway.
@Iheart Nah, you remembered right. I'd be reeeeally surprised if she's truly dead. I wouldn't be surprised if Tasha left some vine she hid alone or somethin' like that. She did hide away her backup in case something went wrong the first time they fought after all.