Spider-UK

Web-slinging {2}{W} (You may cast this spell for {2}{W} if you also return a tapped creature you control to its owner's hand.)
At the beginning of your end step, if two or more creatures entered the battlefield under your control this turn, you draw a card and gain 2 life.

Niambi, Esteemed Speaker

Flash
When Niambi enters, you may return another target creature you control to its owner's hand. If you do, you gain life equal to that creature's mana value.
{1}{W}{U}, {T}, Discard a legendary card: Draw two cards.

Aang, Airbending Master

When Aang enters, airbend another target creature. (Exile it. While it's exiled, its owner may cast it for {2} rather than its mana cost.)
Whenever one or more creatures you control leave the battlefield without dying, you get an experience counter.
At the beginning of your upkeep, create a 1/1 white Ally creature token for each experience counter you have.