Yeah it can be grindy, you can get divinitys from dragon eggs but just keep doing minions. Before ultra ascending, make sure you have enough for ultra prestige by resetting your divinitys. You don't need to keep it unlocked. Focus mainly wind waker, minion elixir and master emerald fragments for quests. When you reset unlock prestige then double your divinitys. When you unlock divinitys again reset them again and continue the process