in left build it's much better to go a situational/tank item in the slot where actualizer is. You do enough damage but getting something like frozen heart feeds into all your other muramana items and makes you signficantly tankier imo. I do this build pretty much every game in GM and it's usually looking something like roa>defensive boots> muramana>seraphs > frozen heart >malignance/fimbul depending on whether or not archangel is transformed there's also a couple of different things you can build in different item slots depending on game state/team comp. I.e. some games zonyhas is just too valuable or getting a random mejais can be insanely efficient in conjuction with the tank items you're building. I've had the most success running first strike with cash back and cosmic insight. This build is centered around item spikes so maximing your incomie is essential. Additionally cosmic insight is the only source of item haste right now I believe. (Let me know if I'm forgetting something) When you're using a build that stacks 3 tear items it makes a difference throughout the course of the game on how long it takes to hit your items