Frequently gaining life will provide you with some wiggle room to pay for powerful effects , such as the activated ability on Aetherflux Reservoir, which can blast an opponent for 50 damage in one shot
I used to play in a lot of tournaments, and Ive played Magic for a long time
It appears that they are explicit abilities, not inherent as in paper Magic, to simplify the rules implementation and type-changing effects in Arena
This deck is built to maximize the suite of incredibly powerful one-mana creatures seeded across white and black in Theros Beyond Death and M21
Other than being red these do not have especially great overlap with Sneak Attack style effects
The card reads: Whenever one or more nontoken creatures you control die, create a green Fungus Dinosaur creature token with base power and toughness each equal to the total power of those creatures. If your creature dies, it just comes back to life as a mushroom dinosaur