30 years ago, Omar, owner of both Blackacre and Whiteacre, executed and delivered two separate deeds by which he conveyed the two tracts of land as follows: Blackacre was conveyed "to Avon and his heirs so long as it is used exclusively for residential purposes but if it is ever used for other than residential purposes to the American Red Cross". Whiteacre was conveyed two bunk and his errors so long as it's used exclusively for residential purposes but if it is used for other than residential purposes within the next 20 years then the Salvation Army".

25 years ago, Omar died, leaving a valid will in which he devised all his real estate to his brother, McNulty. the will had no residuary clause. Omar was survived by McNulty and by Omar's son Cedric who was Omar's sole heir.

For the purpose of this question, it might be assumed that the common law Rule Against Perpetuities Applies in the state where the land is located, and the state also has statute providing all future estates and interests are alienable, descendible and devisable in the same manner as possessory estates and interests.

24 years ago, how would the interest of McNulty in Blackacre be best described? Explain.