Ruzhan's trap terrain obstruction

when casting Ruzhan's trap in narrow spaces, you can end up with as few as 1 rune pretty easily. this feels really bad. targeting needs to be reworked or something. i think what happens is rune locations are chosen before line of site is checked, and if there's no line of site the rune fails. it might be too much to just say all runes land no matter what, that could lead to 21 runes in the same spot, which surely goes against intended design. maybe instead just allow line of site obstructions to reselect another random target some number of times, and if it fails too many tries then it doesn't land.