Shaco ultimate how i would improve it to a more viable option

Hey i am a shaco player and love the trickester diversity and complex playstyle, when playing AP.

His ultimate could work better if the boxes after the initial eksplosion didn't deal damage but instead couldn't be killed either, and making the fear of the boxes scale with AP up to a maximum of "X" seconds (cause right now most dont level it past 1 point. cause it simply is more viable to level your other abilities first, for the higher burst potential). This fix could make AP shaco playstyle as a trickster more viable in teamfights cause he could q into the backline pop his ultimate and have cc when there backline instantly kills his clone while he still is in stealth or making his clone more viable as a way to block escape rutes.

This also wouldn't hurt the AD way of playing shaco who would go for a more "burst" on a target, rather then tricky plays that AP shaco does.

i am kinda eager to here others thoughts about this, cause i really fell like there is so little that would make him viable again, without making him OP :)