These two cards work well by themselves, and their flexibility means they can easily be used in a multitude of different decks
Isshin, Two Heavens as One's ability affects only triggered abilities with conditions that are directly related to attacking, such as "whenever [this creature] attacks" or "whenever you attack with one or more creatures." It does not affect triggered abilities with other trigger conditions, such as "whenever [this creature] becomes tapped." Isshin's effect doesn't copy the triggered ability
Some of them have aged better than others
For the same mana cost we get Resonating Lute, an absolutely ridiculous new card for spell-slinging decks like this one

Synthoids Aang and La, Ocean's Fury Aang, Destined Savior Aang, Master of Elements Aarakocra Sneak Abbot of Keral Keep Aberrant Aberrant Manawurm Aberrant Mind Sorcerer Aberrant Researcher Abhorrent Oculus Aboleth Spawn Abolisher of Bloodlines Abominable Treefolk Abomination, Irradiated Brute Abomination, Terrifying Titan Abomination, World Ravager Aboroth Aboshan, Cephalid Emperor Absorbing Man Absorbing Man and Titania Abstract Iguanart Abstract Paintmage Abstruse Archaic Abundant Maw Abzan Beastmaster Abzan Kin-Guard Academy Drake Academy Elite Academy Journeymage Academy Loremaster Academy Manufactor Academy Raider Academy Researchers Academy Wall Accomplished Alchemist Accomplished Automaton Ace, Fearless Rebel Acid Web Spider Acidic Slime Acidic Slime Acolyte Hybrid Acolyte of the Inferno Acquisition Octopus Acridian Adamaro, First to Desire Adaptive Automaton Adaptive Shimmerer Adaptive Snapjaw Adaptive Sporesinger Adarkar Sentinel Adarkar Windform Adder-Staff Boggart Adeliz, the Cinder Wind Adrenaline Jockey Adric, Mathematical Genius Adrix and Nev, Twincasters Advanced Hoverguard Advanced Stitchwing Advocate of the Beast Aegar, the Freezing Flame Aegis Automaton Aegis Sculptor Aegis Turtle Aeon Chronicler Aerial Caravan Aerial Doombot Aerial Guide Aerie Bowmasters Aerie Ouphes

The full slate will be standard legal and the draftable cards cover the entire mainline series