Of course, they could just switch out, but this is still a powerful and under-utilized synergy that deserves special mention
Dimir requires plenty of mana to get things going, and this can provide an unblockable body to land encoded spells
In the case of Wax / Wane you probably wouldnt play an instant that gives +2/+2 to a creature in a deck, or a narrow effect like enchantment removal
Neverwinter Hydra Cards that let you roll X d6 replay that awesome feeling of casting a fireball in a D&D game and dealing, say, 7d6 damage
However they are also extremely powerful, as many of them tie together multiple archetypes
Ability: Intimidating Jaw As long as this Pokmon is in the Active Spot, attacks used by your opponent's Active Pokmon do 30 less damage (before applying Weakness and Resistance)