Phyrexian Unlife Some might see Phyrexian Unlife as a card that simply gains you 10 life, that does nothing against infect
Kellogg, Dangerous Mind wont warp the format or anything
Midnight Reaper This is the weakest one of the lotbecause all it does is draw tons of cards and make sacrifice decks more powerful
No, burn decks can be viable in various formats in MTG, from Standard to Modern to Legacy
Commander is an incredibly popular format, easily claiming its current place as MTGs most popular in-person game type
Youthful Knight is a 2/1 with first strike, so if it was blocked by Alpine Watchdog, Youthful Knight would deal its two damage first, destroying the Alpine Watchdog before the Youthful Knight would take damage