This card works well with "Convulsion of Nature" as it will allow you to know when a high level monster is on top of your Deck so you can make the most of its effect.
This card combos well with "Plaguespreader Zombie". Send a high level monster, such as a no longer useful "Dark Armed Dragon", to the top of the Deck, and then reveal this card to deal an instant 1400 points of damage and special summon a monster; plus it also keeps you from re-drawing the dead "Dark Armed Dragon".
You can use this card to send "Archlord Kristya" after it goes back to the top of the Deck to prevent a dead draw and do some damage.
In a Lightsworn Deck, activate "Plaguespreader Zombie's" effect, returning a "Wulf, Lightsworn Beast" to the top of the Deck. Then activate "Gallis"' effect, dealing 800 damage and Special Summoning both "Gallis" and the "Wulf". Then either Synchro out for a Level 8 Monster or Tribute "Gallis" for "Gragonith", then Synchro out for a Level 6, or Tribute "Wulf" for "Celestia, Lightsworn Angel" and Synchro out for "Armory Arm". With any of these tactics you can, with 3 cards in hand and no field, establish a firm field presence.
When in your hand, use together with "Deep Diver" to place a high-level monster on the top of your Deck to deal a blow to your opponent's life points as well as Special Summon "Gallis" for easy tribute fodder.
This card combos well with "Field-Commander Rahz"; his effect will place a Warrior Monster on top of your Deck. You can then activate the effect of this monster for a guaranteed chance to Special Summon it.
Use this card in conjuction with "Genex Ally Birdman" and "Koa'ki Meiru Doom". As long as "Doom" remains face-up "Birdman" cannot be Special Summoned by its own effect, but you can still return "Gallis" to your hand to fulfill it's cost. You can use the effect of "Gallis" an unlimited amount of times per turn and burn all of your opponent's Life Points.