Who doesnt love a 2-mana 5/5 that gains life every turn
A 2/2 creature is a lot of value for one mana, so this can be a powerful card if youre able to kick it multiple times
The same is true for effects that would replace having you lose life with some other event
Others like Pacifism and Dissipate I play with now, and then there is Dwarven Miner, easily the best land destruction card out there
The First Doctor is particularly interesting, letting you tutor up the TARDIS when it comes into play and then rewarding you for casting cascade spells with +1/+1 counters
Its a nifty little spell that is incredibly good because it doesnt just target creatures, which makes it incredibly versatile as you can use it to protect a land from a timely Wasteland if needed, especially if you can keep returning the Safekeeping from your graveyard by using cards like Eternal Witness