Ghost Quarter is my pick here, as itll be able to target any land, even basics, and even your own
Having a way to keep a big creature on the board for the low cost of holding a single land open is an essential part of most formats, and Tamiyo's Safekeeping is one of the best you could tuck away for when you're in a pinch
With No Side Deck in Master Duel, Drytron has taken a more middle of the road approach and are running Maxx C and Forbidden Droplet in the Main Deck to improve their odds when going second
Both also require you to already have something out on the board to use them effectively on and as a result he seems to be best suited to the mid range decks
Chaos Burst X TRAP When your opponent's monster declares an attack: Tribute 1 monster, then target the attacking monster
On top of these incredibly powerful themed options, there are tons of high-powered Commander options in bracket four