U Tempo is always draw dependant, with strong opening hands containing a 1 drop, curious obsession, and ideally protection or a cheap counter. Adding white hurts consistency in the manabase (not too badly with shocks and checks, but noticably) and cuts out Tempest Djinn as a finisher, but adds consistency by doubling our number of curiosity effects. We also get access to white protection to supplement dive down if we need more copies of that, and Teferi is a very strong card in UW that could be added perhaps in place of the djinn. Finally, at least post sideboard in a Bo3 version we might find some white answers to Shifting Ceratops which dumps all over U Tempo normally (what fun design )
I found I have been gravitating away from djinn in my historic U Tempo decks and don't really care about losing it. Mostly I swapped it out for Brazen Borrower, who fills the faster clock role along with having a control element and flash speed. So imo the main questions are whether its worth adding a better but 2 mana obsession to the deck, if the added consistency (or other effects like lifelink against pressure) is worth the less reliable mana, if there are other white or UW cards worth adding to the deck, and finally what numbers of all of these cards are ideal?
I'm not particularly good at magic or deckbuilding so feedback wanted on this decklist for Bo1. It's a first draft and can definitely use some optimization as its based off my U Tempo deck that I keep tinkering with and probably making less optimal than it could be lol
Historic UW Tempo (Bo1)
Birds
Protection
Approximate Total Cost:
Edit: Updated with current list, adapted from my old Bo1 U Tempo list that had good results way back in a previous standard.