definiens: as used herein shall mean the acquisition of DAIICHI by a Third Party, a business integration of DAIICI - II with a Third Party by establishment of holding company, or any other form of merger and acquisition of DAIICHI with a Third Party, in each case as a result of which such Third Party shall directly or indirectly ( i ) own fifty percent ( 50 % ) or more of the voting securities of DA II C I - I I, or ( i i ) otherwise have the power to elect, replace or direct fifty percent ( 50 % ) or more of the board of directors or comparable decision making body of DAIICHI ; or ( iv ) if DAIICHI or any of its Affiliates commences legal proceeding s, or assists any Th ird Party to cOlllmence legal proceedi ngs, to challenge the val i d ity of any of the Patents