Nearly all of the elements are able to form hydride compounds:
When s-HOMO Lewis bases interact with Lewis acids to form a complex they are deemed to reduce the Lewis acid: s-HOMO Lewis bases are reducing agents.
The hydride ion is a strong proton abstracting base and nucleophile. H2 is only very weakly basic such that H2, D2, T2, HD, HT and DT hardly seem to be basic at all, yet as they can be protonated to [H3]+ (in the gas phase) they must be Lewis bases.
H and H2 form metallic complexes.
Helium can be protonated under gas phase conditions to [HHe]+ so it is a Lewis base, an s-HOMO Lews base.