Weakenshade is a spell used to drastically weaken the target or disable another's powers. This power has been used by Wilder as his favored go-to spell.
History
In Peru, Wilder reluctantly decided to get his hands dirty and used Weakenshade to disrupt Zhalia Moon's Gar-Ghoul and allow his defeat by Hoffman's Myrmidon. S2E27 In the Salon Museum, Wilder tried to hit Dante Vale with this spell but he dodged in time. S2E28
On Avalon, Wilder used Weakenshade to disable Lok Lambert's Overslam power. S2E30 Wilder later used this spell on Medusa's Island to send Powerbonded Kipperin back to his Amulet and send Lok crashing down to the ground. S2E35
Wilder used this spell in the Professor's castle in a surprise attack, hitting Lok straight in the back and rendering him unconscious. S2E46