Effect updates and description changes can be seen here.
Tsunderplane is sort of an upgraded version of Ice Cap in that it's a good charge monster. It doesn't have much HP, meaning that it will probably die upon attacking. But that is the main point of Tsuderplane, which deals 1 damage to all enemies, including the opponent's health when it dies.
This makes Tsunderplane an alternative to Woshua in combination with Asgore or Same Fate. And unlike the others, Tsunderplane is able to kill cards like Mad Dummy, unless there is a Taunt monster.