The whole idea of boss skills is to put a twist on the standard gameplay. Exploit the mechanics of the app in a way that causes us to strategize, be inventive, and rethink our approaches.
It should work because it's different. It should work because it's a challenge. It should work because our time and effort gets rewarded. Not just by beating the event, but by solving the puzzle.
But block? Block is just fluff. It's the illusion of difficulty. There's no strategy involved. And that's just not fun.
Honestly, I love the game and the Devs. Every so often they're gonna have some very uninspired ideas. I'm not mad about it. But I do sincerely hope they filter through all the complaints to see constructive responses like this thread.
I'd be happy with a block counter. Or a barrier where only one card type hits during certain turns (spam rainbow 9+2 team). If Block is gonna be returning, maybe introduce a 9-turn "reflect attack" skill that can bypass it when the enemy hits. Such a skill would pair well with late turn suicide attackers like Submari and Bancho, too.