I have no soul on Rotos (Wishlist is trash), but I figured I can start saving and buying essences. I think Phantom Touch is great because you only need 5-star soul for 100% chance to proc. On Epics and Legendaries, not having to worry about the 6th star is huge in terms of cost. But here's a question: is it worth the cost?

Supposedly, Phantom Touch gives you 5xATK damage, not subject to crit, but ignores 30% def. A legendary champ will also gain about 500 ATK from the skill, which should put my Rotos just over 5K ATK. If I understand crit damage correctly, 250% crit damage means regular damage is multiplied by 3.5 (itself + 2.5 times bonus damage), but feel free to correct me. So I figure 5X ATK would be equivalent to 1.4X ATK with 250 crit damage (I hope I'm not confusing anyone). Additional 1.4X with 30% ignore defense seems like a pretty good bonus damage, I think. 

I think 5-star split soul costs 100 gold essences (can't keep up with all the names), a 4-star split soul costs 300 silves essences, so it'll be a while before I get there, but hey....better than shooting for 6-stars, right?!

Any ideas or issues I should be concerned with?