Infinity ultron was introduced in the series of what if carrying 6 infinity stones and he became an immensely powerful character of the series.
Eternity was seen in love and thunder having the ability to manipulate time, space and many more powers.
Ikrais one of the most powerful characters of Eternals possessing the powers of flying, telepathy and illusions.
In What if doctor strange pushed his power to limit less where he forced the reality to bend his power to him and became the most powerful sorcerer.
God Loki mastered time travel and in the end became the protector of the multiverse alone in that loop.
Kang is the intellectual genius who can time travel and make illusions with manipulation of timelines.
Zeus is one of the deadliest storming characters in the comics and has the power of Thunder and Electricity.