yugioh millennium cards Konami Yu-Gi-Oh - Legendary Duelists: Ancient when an opponents monster activates its effect (Quick Effect) Millennium Pack | Yu-Gi-Oh! Wiki

It might not be a huge bonus in terms of stats, but even just a little buff to a creature's stats can either push through your opponents defenses or act as a deterrent

Fenrir is a Level 7 EARTH Psychic monster that shares the common Kashtira summoning condition, where you can Special Summon it from your hand if you control no monsters

However, most massive value increases are followed by a pullback, so be cautious when buying during the hype.

Coati Scavenger, on the other hand, can pick up these cards with no problem

While Hypnos effectiveness is somewhat luck-based, it deals 10 more damage than Frosmoth, making it a bit stronger offensively

If there are other Amass cards in your deck, it just creates and grows