thor mtg card x Marvel Cards Reveal: New Set Highlights you may play that card Rand Al'Thor - EDH Silver

The +2/+0 buff is useful because there are many scenes where multiple mice are lined up, and you can trigger Valiant simultaneously, or use it on two [Diverse Mice] created with offspring to deal 12 damage

These abilities can only be used at Sorcery speed, but because the active player gets priority after a card enters the battlefield - you're pretty much guaranteed to be able to use of them before anyone can stop you

Unlike madness, they don't require an empty hand to be reliable, and will thus always work with a Wild Research

So many awesome Dragons these days are legendary, so getting to put them in your deck and possibly make copies is amazing