The difference between Bitter Reunion and other sources of haste is you get something else, too, and that something else is card advantage
Against someone who can't spit flows, though, Clamilton cannot compete
The protection also lasts until the creature eventually gets removed, so you dont need to worry about tapping out to keep your precious creatures safe the way you might with some instants
How does the card fare
Formats Not Legalstandard Not Legalfuture Legalhistoric Legaltimeless Legalgladiator Not Legalpioneer Legalmodern Legallegacy Not Legalpauper Legalvintage Not Legalpenny Legalcommander Legaloathbreaker Not Legalstandardbrawl Legalbrawl Not Legalalchemy Not Legalpaupercommander Legalduel Not Legaloldschool Not Legalpremodern Legalpredh Legaltlr
It sounds simple, but because there are few restrictions on who, or what, you can damage, it allows you to target cards that are Evasive, cards that aren't exerted, and, really, any card with willpower