As per image here below, Tommus can’t attack the boss (Invalid Target). Is it a known bug?
Sometimes after the boss has two characters trade places the screen messes up and there is a mismatch between where they are and where they appear on the screen. From the available moves indicated by circles in your screenshot, Tommus is actually in the back row which is why he cannot attack.
In the screen shot above… I see Tom in the front row. And the circle around him indicates that it’s his move. Farideh is in the back…
Yes, that is what I am saying. The glitch that occassionally happens makes it appear like he is in the front row but the game thinks he is in the back row. I would wager this screen shot is from right after the boss switched Tommus and Farideh but the screen doesn’t show it like that. Note that there are no circles with dots (showing where he can move) in the row next to Tommus. If the game thought he were in that row, he could move to the right. Also note that there are options for him to move in the last row, which is two rows away from where he currently is standing - not possible. These show that the game thinks Tommus is in the last row.