Unlike most cards that offer additional combat, Lightning Runner is not limited to using the effect once per turn
You can sacrifice Selfless Spirit over and over to give indestructible to your creatures, and so on
Are they all elf lords, or are they more generic like Tyvar, the Pummeler
Surveil Lands Surveil lands like Undercity Sewers are a huge upgrade to scry lands for multiple reasons
If that creature has X in its casting cost, you put +1/+1 counter on it equal to the number of lands you control
There are only 3 other cards that reference exploring, but two of the payoffs -- Nicanzil, Current Conductor and Topography Tracker -- are both incredible, definitely worth it if Hakbal is your commander but the first cuts if you swap commanders