The best thing this does is as a space efficient tool for streamlining sideboards
Like I mentioned above, several monsters lock you out of Anaconda plays for the turn (Faris and Cross Crusader), so be careful
Pokmon Black Bolt and Pokmon White Flare will also feature illustration rare cards of all 156 Unova Pokmon, a first for the trading card game series
15 of them will be available in week-long events called War of the Spark Sagas (the first of which is already underway)
Lost Origin is another strong option, featuring Giratina V Alternate Art, which has some of the best artwork of the era, and Aerodactyl V Alternate Art, which has been climbing in value
Any existing effects or counters that raise, lower, or switch a creatures power and/or toughness continue to apply to the creatures new base power or toughness