Merfolk Spy A creature with islandwalk for 1 mana is a nice way to start off the game and hopefully lets you do some early damage
And while that's cheaper than our next entry at #5, like it, you really need four to party
There were some staggering gains in Modern this week now that we know what key staples dodged a reprint in Masters 25
Because you are redirecting the target of any spell or ability you have a lot of power here that Blue answers would normally lack
Obviously, if you have graveyard synergy, flashback, or cards you want to discard, the effect is all upside, but you don't have to go this far
For just 1 mana to cast and two to equip, this Legendary equipment gives a Creature two of the best combat keywords you could possibly ask for: Trample and Lifelink