This is great as is, but the activation to trade three rats to reanimate potentially multiple creatures has a very high power level
If an effect causes The Warring Triad to lose all abilities, its ability that causes it to stop being a creature still applies if appropriate
Editor's Note: Previous MTG Arena Announcements stated that June's events would qualify players for Arena Championship 9
The reason is that suspend replaces the act of casting a card, and you can't convoke the alternate cost of exiling it from your hand
If you have the Hat in play and play Reflection (you can sing it also for free, but one is not a steep price to mitigate) you will then be able to immediate draw one guaranteed off the Hat, then the next draw will be off the top (start of next turn), and you can use the Hat to guarantee hitting the third card (assuming you can easily remember the three cards in order without taking notes)
Its strongest synergy is with Altar of the Brood