Besides its obvious implications in Mardu EDH decks already built around attack triggers, in formats like Standard you can benefit from multiples of these
Every time the equipped creature connects with a player, you get to surveil 2, moving cards from the library to the graveyard if you choose, and then giving you a free spell so long as that spell costs two or fewer mana
Like most Magic: The Gathering cards, the value of Mountain depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (European Land Program)
This means Lara deals 3 damage, and can take 4 damage before dying
In general, a 2/2 flash creature is worth a little bit more than a Shock