Sabre Cats begin with Cold, Fire and Lightning Resist 50% in Hell, but
Dire Touch does not become
Immune to Fire or
Immune to Cold because
Magic Resistant gives her Resist 90% (50+40) before Spectral Hit is applied.
Pulse Fester does become Immune to Fire and Immune to Cold because Spectral Hit gives her Resist 70% (50+20) then Magic Resistant gives her CR 110% then FR 110% (70+40), while she remains at LR 70% since applying LR +40% would result in a third immunity.