This can happen if a Monster has a condition that allows you to Summon itself (Cyber Dragon) or through the effect of another Monster (Summoner Monk) or Spell/Trap (Mimicat)
Budget based on set size, and start buying singles 2-3 weeks after release when hype pricing settles
Some of them feature Ultra Beasts extradimensional Pokmon first introduced into the franchise with the Sun and Moon game remakes which makes them worthwhile pick-ups for collectors
This card, Aurelia, the Warleader, is a powerful card that would benefit a Boros (red-white) aggro deck in Magic: the Gathering
Meanwhile, cards such as Kronk, Junior Chipmunk and Beast, Forbidding Recluse are able to dish out damage on top of their own strength, whittling away your rivals defences
Theres a smattering of other random staples thrown in here too, like Mana Drain, Swords to Plowshares, and Necropotence