You choose all of your modes at once
Some argue that you should only use proxies for cards that, due to scarcity, have reached a ludicrous price on the secondary market (check out our guide to the most expensive magic cards for some of those) or for Reserved List cards that are almost impossible to get hold of
Chaos Warp is a fine start, with the mystical archive version being worth about $6, according to MTG Goldfish
I was kind of perplexed on whether the number of seats should be listed by text, but I agree with you now that you mention it, the text has become obsolete due to the visuals on the card
Essentially, the target must discard one card per black mana used, making it a super powerful option capable of winning games for players
The artwork on the cards includes pink and purple broken glass shards as the backdrop and frame of the card name and text box