One thing I learnt painfully with Loki was that the "Replace" is literal. If you only have 1 card when you played Loki, then you'll only get a random 1 card from the opponent's deck.
Which means I can't slot him in normal decks without a hand-increase card like Smith or Fury.
What happens when you don't read!
But the card is really fun. I felt the feeling of "having options" after a long long time. The balance of uncertainty vs "knowing thy enemy" finally feels natural. For once, mirror matches are quite fun and crazy.