At first glance, the effective mana cost of this effect is 3 mana (2 mana to activate, and 1 opportunity cost mana from having to tap itself) but upon closer inspection, since it finds you an untapped basic land which you can then tap for mana, you effectively get refunded one of the mana, and the actual effective mana cost of this effect is 2, which puts it on-par with Tectonic Edges mana efficiency
Since it isnt an alternative cost itself, it can be used alongside an alternative cost
The decks below apply this in two ways: one quickly spreads damage, then ramps up bench damage to finish
The whole sheet is very art-forward, so the cards are less thematically cohesive and more just a pile of reprints that made sense with the Spider-Man art they wanted to use
The recent Sonic the Hedgehog Happy Meal promotion officially came to an end today, but McDonalds now has free items based on a totally different video game property