That makes Entei an interesting double-edged sword: if you want to get the most out of Entei V, you have to risk taking more damage from an opponent's one as well
You could literally just take the 24 or so highest rated spells according to my archetype breakdown for them and put them with the best land and have a great deck
Sensei's Divining Top Sensei's Divining Top is another original member of the Modern banned list, but instead of power-level concerns (although it might be too good now, thanks to the miracle mechanic and Counterbalance, giving Modern access to most of the pieces of the now-banned Legacy Miracles deck), the main reason the artifact was banned is because it slows the game down to a halt
Readying of Rites Normal Spell Card Add 1 Fiend Ritual Monster from your Deck to your hand, then if you added a Pendulum Monster, you can Special Summon 1 "Sacrificial Offering Token" (Fiend/DARK/Level 1/ATK 300/DEF 300)
You try and whittle down to only the best options, but the choices get harder and harder the deeper your decision tree leads you
The one other card I wanted to call out was Magic 2010