While giving 500 Attack is beneficial, and forcing your opponent to target your stronger monster can be helpful, The Seal of Orichalcos is very restrictive
Endless Atlas is a great card in any mono-colored deck, and Reliquary tower is always good in decks that like drawing cards
There may be others out there, but these are the big ones: classified ads (of which Craiglist is likely the most popular), Ebay, and your Magic social circle (this includes Facebook groups, friends, local gaming stores, and players in your local area)
Use rigid top loaders or magnetic cases
But where they do need a lot of help is getting to the point of the game where those threats are castable whether through ramp, or just putting on pressure and defending yourself with low-mana creatures
In Duel Masters Charge he was believed to have been killed in a duel against Zakira