Wanting a non-Trans build so I do not have to compete with Trans Hunters and Book Mages, I found this to be very useful in non-Conquest modes so far.
Start - Attacker's Blessing (early game advantage) + Tier 1 Mace
Build
First three items in order
1 - Talaria Boots, while you lose 20 power of Warriors you gain MP5 for ability spam and higher movespeed for positioning.
2 - Jotunn's Wrath, CDR mainly plus Power and Pen.
3 - Soul Eater, easy to stack and Passive helps keep you alive.
Next 3 in whatever order you feel best
4 - Crusher, mainly for Passive. Alternate item Heartseeker if you can get the 5 AA stacks, better Passive plus more MP5.
5 - Shifter's Shield, good defense especially at low health plus nice Power at high health.
6 - Masamune, bit more defense, move and power. Really you can flex other items of choice here.
Going to see if this works with some tweaking for other ability Assassins, Hun Batz for example could replace Jotunns with Hydras as he likes the Passive better and needs the CDR less as abilities rank up.