Include enough damage-dealing options to threaten your opponent while having defensive tools to protect your strategy
Hiram Flaversham has been around since the earliest days of the game, so its removal will definitely be felt in competitive play, especially with the approach of the Disney Lorcana World Championships later this year
With an impressive three lore, and an ability that is going to really make your opponent think twice about banishing him, Milo King of Atlantis could be a powerful ally to Emerald decks when used well
Tabletop Simulator has no matchmaking, so you will need to arrange games manually with other players, or consult a Discord channel where other players are gathered
(Lorcana.gg) TL;DR quick reference Sapphire/Steel is still a tiered contender thanks to efficient ramp, sticky midgame bodies, and clean removal