The #1 Indicator: The Shrink Wrap (Cellophane) 2
All of the main deck monsters can special summon themselves for a free Synchro, Xyz or Link material, despite their main effects restricting the Extra Deck
If cards become worthless, many fewer packs will be opened
If the total Levels of monsters used for this card's Ritual Summon were 2 or less: You can destroy all Spells and Traps your opponent controls
The Vanquish Soul archetype, fittingly known as VS in Japan / the OCG, is a series of cards themed around fighting games especially the anime variety like Guilty Gear and BlazBlue
Getting the requisite ritual cards to hand is pretty easy, thanks to the card fetch effects on monsters such as Manju of the Ten Thousand Hands and summoning spells like Impcantation Thanatosis , which will also destroy an enemy card when a ritual summon is performed