Another way is to reduce the cost of those cards in general
His conditional indestructibility has the potential to turn off kill cards from decks that dont have early drops or cant keep them on the table, and his recursive potential is unlocked by any deck that either a) plans to use Delve (Tasigur, Angler, Treasure Cruise, Dig Through Time) or b) plans to abuse Deathmist Raptor and Den Protector
On top of that, some playgroups will go through "Rule 0" discussions before playing Commander, essentially self-regulating games by establishing power levels of decks and asking if some cards are fine to play
Basically, players can sacrifice the card to grant indestructible to an allied creature along with a piece of equipment Zack Fair once used
Unfortunately, Fist of Suns will not save you from paying the commander tax
As I said, this format is defined by the pursuit of subjective goals over competitive advantages