Each one has its own restrictions, but the sheer power level of these cards is impossible to overstate
By itself, its already a 2/3 deathtouch creature that generates 2 mana of one color, easily ramping you into 6- or 7-drops
Other cards revealed in the stream today show the range of powers and potential archetypes available to players, including Fierce Empath, which can help you find huge creatures hiding in your deck, and Runed Halo, which can offer a lot of protection against decks aggressive or tricky decks, and Teferi's Ageless Insight, which will allow players to draw tons of cards (everyone loves to draw cards!)
These can give you a two-for-one-trade at best
If it's a permanent spell, the copy gains haste and "At the beginning of the end step, sacrifice this permanent." (A copy of a permanent spell becomes a token.) Creature - Beast Demon Color tag templates(None) Nightscape Familiar Blue spells and red spells you cast cost less to cast
But look at your other legendary creature (and potential commander) Alibou, Ancient Witness