Does the prayer of one who intended to invalidate his ablution, then retracted that intention and prayed with the same ablution, become void? And is the intention to invalidate ablution nullified by mere intention?

If someone intends to nullify their ablution (wudu') but does not actually do so, their ablution remains valid and is not invalidated merely by the intention to nullify it, unless an actual nullifier occurs. The Fiqh Encyclopedia mentions that the intention to nullify ablution after completing it does not invalidate it according to the Shafi'is, and similarly for the Hanbalis regarding prayer, fasting, and Hajj. As for the Malikis, they hold that rejecting the intention of ablution or ritual bath (ghusl) after completion does not cause harm and is not considered among the nullifiers.