most valuable dr who mtg cards Universes Beyond: Doctor best put a +1/+1 counter on each creature you control that didnt attack or enter the battlefield this turn Magic: The Gathering Doctor Who

, Remove an indestructible counter from Arwen: Another target creature gains indestructible until end of turn

The first does it for basics, some later ones like Farseek do allow nonbasics with that card type

Or you could run them both in Highlander decks although for flashback I'd prefer Deep Analysis to Think Twice, since it's just one more mana total for twice as many cards but a loss of life

It allows you plenty of space in the single-player mode and can also connect you with other players for real productive testing sessions

The trick part is figuring out which color to splash into because pretty much every color offers potential