mtg blue search your library for a card One Mana When Spellseeker enters the battlefield Mystical Tutor

There was Accelerated Blue and the German Dragon in Standard, Suicide Brown and Iron Giant in Extended, good old Yawgmoth's Bargain in just about everything that allowed it, and then a lot of descendants of those initial Tinker decks that continued to get refined and grow in power until they took over Extended in New Orleans

It's easy to reuse the ETB ability with cards like Displacer Kitten or Teleportation Circle, making this an excellent finisher that prevents your opponents from maintaining a board state

I mean, he's not good , but he's a 5/5 that costs four mana to summon

You can then pay two life and tap Hazel to use those tokens as mana dorks

Arcane Signet can help you with mana fixing

A piece of equipment that not only can double-up on activated abilities and grants vital haste to a creature that may well need it to function