Instructions
1. Create seasonal hero
2. Complete challenge rift (video guide will be on YouTube)
3. Open cache (35 DBs & other mats)
4. Take follower's weapons
5. Go get Kanai's cube in Act 3 Ruins of Sescheron
6. Level up Blacksmith & Mystic
7. Craft class-specific item (and spend blood shards)
8. Upgrade item in cube (Recipe 3) and cube power if you got something good (Recipe 1)
8a. If you got an ancient weapon with a bad power, keep it to reroll reduced level requirement by 40
9. Spend blood shards (consult https://www.d3planner.com/game/60803/...)
10. Craft a 70 2H with life on hit and a slowing effect as the secondary
11. Reroll the OTHER secondary to the best reduced level requirement you can get
12. Complete an easy boss bounty for yellow items (Zultan Kulle, Maghda, etc)
13. Do rifts on hard until you reach your cube power and/or lvl 70 weapon then move to at least T1
13a. You can also do massacre bonuses in Halls of Agony Level 2, or the cleave strategy on T6 in Halls of Agony Level 1
14. Buy +dmg rings and amulets at lvl 7/10
15. Craft a new 2H every time you can until you reach your lvl 70 weapon
16. Once 70, complete season journey for set and do low level GRs to get legendary gems

What to upgrade
Necro 2H Scythe
Demon Hunter 1H Dagger
Witch Doctor  Mojo (or VD Masks)
Wizard 1H Wand
Barb 2H Mighty Weapon
Monk 2H Daibo
Crusader Crusader Shield