Unlimited power!, sometimes known as Unlimited POWAAAAHHHH! is a memorable quote said by Sheev Palpatine during the Duel in Palpatine's Office, shortly after saying "I’m too weak." Anakin then cuts off Mace Windu’s arm. Clearly not too weak, Sheev blasts Mace with a powerful blast of Force Lightning. It is commonly used also as a reaction image towards the feeling of power, usually ironically. It's also commonly used alongside "I'm too weak."
Panel meme form
Another form of the meme is used, utilizing the irony of the original quote. Typically, it's used in a fashion such as one is weak, until something occurs, motivating the previously weak entity.