Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{R}: This enchantment deals 1 damage to each creature and each player.

Jon Irenicus, Shattered One

At the beginning of your end step, target opponent gains control of up to one target creature you control. Put two +1/+1 counters on it and tap it. It's goaded for the rest of the game and it gains "This creature can't be sacrificed." (It attacks each combat if able and attacks a player other than you if able.)
Whenever a creature you own but don't control attacks, you draw a card.

Chatterfang, Squirrel General

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)
If one or more tokens would be created under your control, those tokens plus that many 1/1 green Squirrel creature tokens are created instead.
{B}, Sacrifice X Squirrels: Target creature gets +X/-X until end of turn.

Captain America, First Avenger

Throw ... — {3}, Unattach an Equipment from Captain America: He deals damage equal to that Equipment's mana value divided as you choose among one, two, or three targets.
... Catch — At the beginning of combat on your turn, attach up to one target Equipment you control to Captain America.