Illusion
Behold the power of the Ultimate Idol!
Joseph nodded to Lancer in understanding. To have the summoned spirit bruised and scuffed up while attending the meeting could put them at a disadvantage, especially if alliances formed and less than scrupulous actions were taken by the other Master-Servant pairs at the gathering...this simply wouldn't do.
"Lancer, we'll have to stop by the house and grab our ace in the hole before we go to the meeting. We can't risk combat if you aren't in peak condition, and I would like to apologize for the inconvenience you faced from handling those criminals." Indeed, if they brought that to the meeting, there would be no need to worry about any movements from other Masters...
"Make sure I don't accidentally use it unless it's absolutely necessary, Lancer. That thing would do more harm than good in anything but the worst case scenario." Joseph solemnly spoke to the astralized hero as he began a lively jog toward his home and base of operations.
Poor scrubs won't stand a chance against the mighty LANCERWEAPON!
After having a mental discussion with his master, Lancer eventually relents with the plan. He didn't think it was necessary but he supposed drastic measures had to be taken. Especially at an important meeting such as this.