They also won't trigger if a card on the battlefield transforms into a card with the legendary supertype, the artifact card type, or the Saga subtype
Legendary Creature - Rogue Devil Krav, the Unredeemed Partner with Regna, the Redeemer (When this creature enters, target player may put Regna into their hand from their library, then shuffle.) , Sacrifice X creatures: Target player draws X cards and gains X life
Whats nice is that this should be very good in just one deck while no other deck will be particularly interested, so you should be able to pick it up whenever you need
Now, lets switch tack a little, and talk about ways to fight back
Kindred Summons is kind of absurd because of how powerful it is
In that scenario, you probably imagined an opponent with 0 life, and you with some attacking creatures