Summon "Lava Golem" to your opponent's field, then follow up by Summoning "Relinquished" and take it as a Spell Card. Attack with "Relinquished" for 3000 damage, then "Mystical Space Typhoon" your "Lava Golem", followed by this card to Summon "Berserk Dragon" for 3500 more. (Though not necessarily on the same turn.)
If a Ritual Monster Deck is ran, your Deck will inevitably be filled with Level 8 monsters. If a level 8 Ritual Monster is Ritual Summoned from your hand by Tributing another Level 8 Ritual Monster on the field, this card can be used afterwards to get a free "Berserk Dragon" to clear out your opponent's monsters without losing any field presence.
The effect of "Gagaga Magician" can be used to turn it into a Level 8 monster, and then attack a monster with higher ATK, so "Berserk Dragon" can be Summoned.