In Giselas case, thats double damage for any source damaging opponents or their permanents, and incoming sources of damage halving, rounded up
Chart shows the price of Druddigon #TG09 at the end of each month going back as long as we have tracked the item.
This time, if you would pay life for an effect, you can exile that many cards from your library instead - that's great in big deck formats like Five Color and Commander with a lot of fuel
It slows down decks that try to cast multiple spells in one turn like Storm, Tron, or Cascade, and it also messes with greedy mana production
Three sounded like a good number I thought
One will die to the legend rule, which will then give us a 2/2 non-legendary token copy with Ratadrabik of Urborg's ability