Sword of Dungeons & Dragons

A unique sword, whose blade is crafted to resemble a mace on one side, and a scimitar on the other. It’s brass handle curves in the shape of a coiled dragon, and affixed to its hilt is very solid icosahedron. You have a +2 bonus to attack and damage rolls made with this weapon, and while wielding it, you have immunity to damage from attacks made and spells cast by clerics and rogues. Attacks made with this weapon also deal an additional 1d8 poison damage and 1d8 piercing damage. Additionally, whenever you deal damage to a creature with this weapon, you can use a bonus action to summon a gold dragon wyrmling in a space of your choice that you can see within 15 feet. The dragon acts on its own turn in initiative, is friendly to you and your allies, and follows any commands you give to it. After summoning the dragon, roll a d20. On a result of 20, you may summon another dragon and repeat this process.