Bastilla moded for high protection not health is immortal.

I watched urzas stream where he faced Bastila with hoda can't remember who else or if it was 3v3 or 5v5 but he lost lots of toons. We made urza to check his mods and this guy moded her for protection. Can't remember how much health secondaries she had or if the mods were health mods but she was immortal maaaan. Can anyone explain this?