@deathmailrock My ideal Tsundere arc would probably be close to the one in NGE with Asuna and Sinji, but not 1 to 1.
Generally, I like it to go along the lines of:
1) The tsundere gets upset with MC when MC deserves it and not because of some misunderstanding. She tries to appear competent and in control on the outside and to those around her
2) The Tsundere has her own internal issues she is facing and is expressing her misplaced emotions through her anger tendencies. In comedic scenes, she should never get more violent than a gentle slap or a stomp, but nothing that would leave lasting damage. (Unless the joke is something to the effect of she is so powerful that she can not control herself and she sends MC through a wall or something.) If the scene is serious and the tension between the two keeps escalating until she gets violent, it should portray her as in the wrong or as a breaking point between the characters. For instance, say she hits him very hard, and he decides to leave on his own, and it causes FMC to get introspective and reevaluate her actions and her relationship, and then it makes her change her approach in the future
3) If the MC is dealing with emotional issues of his own, she should be able to realize not to let her tendencies get the best of her and exhibit self control. Perhaps she starts to get angry with him over a sensitive subject and stops herself because she realizes she's hit a nerve or that he's getting emotional. Maybe even show him crying after she starts to get too personal and have MC run away, for her to chase him down to apologize. The idea is that she should be their to support him and to indicate she has just as much investment in him as he does in her and that the relationship is reciprocal.
4) FMC should be able to have normal conversations with MC and not always be so stuck up, such as gradually becoming more open to an event or getting more relaxed around him as time goes on, but just keeping enough spice to keep the dynamic interesting
(Note: I say "her" but the genders can be swapped with this and it be fine. I was just thinking of NGE)
Essentially, you have to walk a fine line between cruel enough that it's clear she's a tsundere and that learning to overcome it will be her arc versus being too cruel and losing the audience's sympathy