spell steal

Hi. Is the title possible to do in any way that's reliable? Secondary target meaning the one that gets the buff/debuff after it getting removed from the primary one. I likely already know the answer which is to make a custom Spell Steal instead and do everything myself, but maybe someone knows...

I made this spell based on Steal Spell: But my problems are: I wanna make a "lightning snake" that looks like that absorbs the essence of the target, to do that I use two units to the position of the head and the tail, it worked but sometimes those unit get stucked and I don't know why. I made...