This is a casual deck built around a Legendary theme, helmed by Arvad the Cursed, a cool uncommon legendary card that boosts almost all of your creatures. And what to do with this army of legendary awesomeness? Beat the living crap of your opponents, of course!
Arvad the Cursed may give +2/+2 to your army, but it's not the only one to give bonus to legends.
Elesh Norn Grand Cenobite pumps your creatures while weakening the opposition. Day of Destiny, Ravos, Soultender, card:Heroes' Podium and many other cards will make your legendary army bigger and meaner to smash other players, while card:Odric, Lunarch Marshal, card:Masako the Humorless will give some other kind of bonuses, making you confortable for all out attacks.
Dominaria gave some nice toys for a legendary theme deck. And one of the greatest are Yawgmoth's Vile Offering (which is the only card with a Yawgmoth picture in all of MTG) and Primevals' Glorious Rebirth. Both cards return creatures from your graveyard to the battlefield, with Primevals' Glorious Rebirth being fantastic to restore all of your army to full power in no time.
However, you can count with Yomiji, Who Bars the Way and Sheoldred, Whispering One to return all of your legendary creatures to the battlefield or to your hand, saving them from death. Or better yet, Avacyn, Angel of Hope will turn your board indestructible and ready for everything (except for mass exiles, nothing can be perfect).
As your army of heroes rise, it's almost certain that your opponents will try to cast mass removals to stop your advancement. You may have reanimate options and cards like Teferi's Protection and Avacyn, Angel of Hope for protection, but many mass removals can ruin your day easily. Actually, any anti-creatures strategy can be quite problematic against this deck.
As if it wasn't enough, if you empty your hand, there are not many draw spells or cards that can help you. Sure, there are some like The Immortal Sun and Phyrexian Arena, but there are few and far between.
Overall, the deck really wants to play an agressive to midrange strategy, favoring combat and legend synergies to overcome your opponents, having options to reanimate them. It is a casual deck, but it can be really powerful and can be a blast to play, but take care with mass removals and hard control players.