Mathise, Surge Channeler is a rare Legendary Creature — Human Elf Shaman Sorcerer card from Secret Lair Drop (SLD), collector number 1238. Current market price: $6.98 (foil $9.38), TCGplayer market prices via Scryfall.
Whenever you cast an instant or sorcery spell with mana value 3 or greater, roll a d20. 1-9 | Each player draws a card. 10-19 | You draw a card. 20 | Copy that spell. You may choose new targets for the copy.