If those costs are only 3, 2, or 1, that equip ability will be free to activate if it targets Fervent Champion
The ability is essentially a tweaked cascade, but excludes non-permanents, doesnt care about CMC, and gives you the choice of putting it in your hand instead (for the sake of mutating)
As for the cards themselves, the design is amazing
Brawl Legal Vintage Legal Timeless Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Legal Toolbox Buy This Card Notes and Rules Information for Drogskol Reaver: If Drogskol Reaver deals enough first-strike damage to destroy each creature it's blocking or was blocked by, it won't deal any damage during the regular combat damage step and its last ability won't trigger a second time that combat
The demand is usually low for random crimps, but once it hits a card people collect, like a Lightning Bolt or something, the very meager supply of any given card will kick into play full force