It's tough in hell for shapeshifters so far—we definitely know that the best Diablo 4 Druid build is not putting all your points in 'bear'. Instead, why not try becoming a lightning-based storm druid who can immobilize enemies by chaining together shocking Storm Strike bolts? This build leans towards the endgame, really coming into its power when you unlock a huge slew of storm-based passives at the Druid's fifth skill tree node. Notably though it doesn't involve a ton of beast transformation—sorry, bear fans.
The Diablo 4 beta in May has a level cap of 20, so be warned that a lot of the passive benefits and crowd control stacking this build aims for won't be unlockable until the full launch in June. For the beta, try snagging a few earlier skills to supplement your build like storm skill Tornado and werewolf skill Shred.
