So...<br/><br/>Custom item...  I need feedback because I've never done high level 5e.<br/><br/>This<em>does</em>split into two items.<br/><br/>So, this is a sword set with a Ruby of the War Mage.<br/><br/>Individually, the two items require separate attunement.  the sword is a +3 weapon.  The ruby just causes a weapon it's set in to act as an arcane focus.<br/><br/>Combine them and they only require one attunement.  The sword is still +3.  it's an arcane focus.  When i cast a spell while holding the arcane focus, the spell gains +3 to attack rolls and  ignores partial cover.<br/><br/>Is that enough to be on par with a legendary item?  Maybe i should look closer at my storm focus...