mtg cards like grave pact Whenever a creature you control is put into a graveyard from the battlefield Magic the Gathering - Grave

Why is chaining extra-turn spells called out specifically

If you choose to pay two ink, she can deal damage to opposing characters after a song has been used

Time Reversal lets you do the same thing for 2 extra mana, but you can play it again by retrieving from exile back to your hand with cards like Riftsweeper and Pull from Eternity

Barbed Bloodletter Cinderbones Corrosive Mentor Massacre Girl, Known Killer Massacre Girl, Prime Killer Midnight Banshee Necroskitter Needle Specter Oddric, Lunar Marquis (playtest) Sickle Ripper Smoldering Butcher Wither and Bloom

The main difference is that because you dont get to use your sideboard, youre much weaker against your bad matchups