With Kris on the board, your entire team will power up with each attack, giving the attacking monster +1/+1 for each other ally monster on the board, with a max of 2.
Keep in mind that Kris doesn't benefit from this effect itself, but since it will count towards the needed other monsters, any of your other monsters that attacks will get +1/+1 or +2/+2 before the attack hits its target, dealing more damage and be more likely to survive the counterattack.
This makes Kris a perfect support card, and due to it being Determination, its effect can't be silenced either.
Kris can be used with other support monsters like Hathy to increase a monster's attack by 3 and Ralsei to make the monster immune to damage when attacking. If combined with Hathy and the Veteran Artifact, a monster can gain up to 4 attack and 2 health each time it attacks an enemy.
The way to counter Kris is through cards that remove it from the board such as Endogeny, Expulsion, and Dimensional Box. It can also be removed from the game by changing it into another card through the use of Chaos Duck .
No other card shares the same cost as Kris will be changed into a base Kris if Red Bird is used on it.