I have two thoughts on that. A.) Vesin would be the most likely to use the simulation at this point in time for training. And B.) He'd be the kind of guy who would want to take on Chara just for the hell of it.

Description: | Name: Chris Deadman | Age: 19 | Species: Human | LV: 25 | HP: 85/210 [150 normally, Terrie`s soul boosts it by 60; with full DETERMINATION, it gets boosted to 2100; if Chris dies, Terrie`s soul will break apart instead, saving Chris from truly dying] | ATK: 250 | DEF: 25764 (14 normally, Locket boosts it by 25000, Boarder's soul adds 100, Terrie`s soul adds 650) | Essence: Infinite | Quiet, analytical, not very expressive, confirmed psychopath | Asexual, panromantic | Ambient Theme: https://www.youtube.com/watch?v=1mCg9oGvVk0 | Analysis Theme: https://www.youtube.com/watch?v=uy_MFtTFhd8 | Battle Theme: https://www.youtube.com/watch?v=0Muucyonpxo \\Lovely sprite made by the equally lovely Derp!\\