Like most Pokmon cards, the value of Steelix depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Plasma Freeze)
"The cards have serial numbers, and no boxes are the same
The reason is simplejust by returning a Pokemon card from your hand to your deck, you can search for any Pokemon card you want, making it a true game-changer
Basically, you can not only see the future, but also invest in it
Much like Crested Sunmare, this checks on everyone's end step, so find some ways to gain 5+ life at instant speed on opposing players' turns (or block and pump)
Casting spells for free from your opponents graveyards is one thing, but then having them lose life equal to the mana value when you do cast them is pretty nutty