What are the best strategies for building a competitive deck using copy cards in Magic: The Gathering?

When building a competitive deck using copy cards in Magic: The Gathering, focus on including versatile copy spells that can mimic powerful opponent's cards. Use cards that can copy creatures, spells, or abilities to adapt to different situations. Additionally, consider including cards that can generate card advantage by copying your own powerful spells or creatures. Lastly, make sure to include cards that can protect your copy spells from being countered or removed by your opponent.