It is the ongoing nature of the life gain combined with its cheapness that make it so dangerous for aggressive decks
In a format like Modern that is so dominated by Cascade triggers and Evoke Elementals like Fury with insane enters-the-battlefield effects, Tishanas Tidebinder seems priced to find a home
A planeswalker-only strategy is difficult to pull off in faster formats like Modern or Legacy since they generate value over time rather than impact the game immediately
Legendary Creature - Vampire Angel Recursion (CTRL to add secondary) Removal Removal (CTRL to add secondary) Tokens Felisa, Fang of Silverquill Flying Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) Whenever a nontoken creature you control dies, if it had counters on it, create X tapped 2/1 white and black Inkling creature tokens with flying, where X is the number of counters it had on it
Separate, but related are cards that trigger when they leave the battlefield
Here is also where packages might begin to change in size