Nadu, Winged Wisdom , was previously banned from the Modern format for introducing an overpowered combo
The one rule of lifegain: sources feed payoffs A lifegain deck has two halves, and it is dead without both: Sources cards that gain you life, ideally incrementally and repeatedly (lifelink, whenever a creature enters triggers, upkeep gainers)
Unsettled Mariner counters a spell or ability from your opponent unless they pay one generic mana
The card ended up getting named after me, so I bought the art, and it now sits in my den along with my three other pieces of original Magic art (Jester's Sombrero and Look at Me, I'm the DCI from Unglued and Mise from Unhinged )
Ygra, Eater of All from Bloomburrow changes all that by turning all my creatures into food
Here are some common examples: Creature types : Goblin, Elf, Dragon, Zombie, etc