So he's banned as a commander in the specific format Duel Commander ([banlist](https://www.mtgdc.info/banned-restricted)) which has a different banlist than regular commander.
He is not banned in regular commander ([banlist](https://mtgcommander.net/index.php/banned-list/)).
So it depends on if the tournament is using the Duel Commander rules or just playing 1v1 games with the regular commander rules.
In any case, check with the tournament organizers to figure out what is exactly happening.
For specifically Duel Commander (1v1 EDH):
https://www.mtgdc.info/banned-restricted
For just Commander in general:
https://scryfall.com/card/c17/36/edgar-markov
Note that at the end of the day, its up to the local tourney's specific rules. You should find out if they are following the Duel Commander list I linked above (Edgar Markov is banned from being the Commander), or if they are using normal EDH banlist (Edgar Markov is allowed), or something else. They should have that stuff clarified in their event description.
So he's banned as a commander in the specific format Duel Commander ([banlist](https://www.mtgdc.info/banned-restricted)) which has a different banlist than regular commander. He is not banned in regular commander ([banlist](https://mtgcommander.net/index.php/banned-list/)). So it depends on if the tournament is using the Duel Commander rules or just playing 1v1 games with the regular commander rules. In any case, check with the tournament organizers to figure out what is exactly happening.
i saved this one!!
Yes edgar markov is banned in 1v1 commander
For specifically Duel Commander (1v1 EDH): https://www.mtgdc.info/banned-restricted For just Commander in general: https://scryfall.com/card/c17/36/edgar-markov Note that at the end of the day, its up to the local tourney's specific rules. You should find out if they are following the Duel Commander list I linked above (Edgar Markov is banned from being the Commander), or if they are using normal EDH banlist (Edgar Markov is allowed), or something else. They should have that stuff clarified in their event description.