Like most planeswalkers, your goal should be to activate his ultimate ability, which gives you an emblem that can generate a ridiculous card advantage and life gain given the power of most Demon cards
At best, I could see Harold as a sideboard card to punish control decks that tap out for a sweeper or threat, but the original dream of one-shot people out of nowhere was getting further and further away even as the list improved
(There are currently eleven
Its hard to argue that a white deck shouldnt be playing this card, and even if your opponents arent greedy enough to ignore paying the one, you can easily buff it with equipment, counters or anthems, leading to almost guaranteed card draw
(You can change numerals or number words.) : Reveal the top eight cards of your library
Did Bob Ross Really Make/Draw Magic Cards