Huh.

It's unfortunate that the indestructible will come to late for this to survive the combat another Rat dies in.

I'd consider "At the beginning of your end step, if ~ died this turn and another Rat you control died this turn, return ~ to the battlefield."

Though that ability probably is cool enough to make its own design, while the tribal indestructible here seems more like something to serve the immense repeated removal ability.

I'd prefer "up to one target" over "you may".

I was honestly thinking about sacrifice strategies, though there isn't an abundance of those in this specific set.