Level 8 WIND Insect/Effect 2700/1600

You can Special Summon this card (from your hand) to your opponent's side of the field in Attack Position, by Tributing 1 monster they control. If your opponent controls a "Kaiju" monster, you can Special Summon this card (from your hand) in Attack Position. You can only control 1 "Kaiju" monster. Once per turn, during either player's turn: You can remove 3 Kaiju Counters from anywhere on the field; the ATK and DEF of all other monsters on the field become halved. 

Level 8 isn’t the best, but it’s WIND so you can use Slumber to your advantage. 

Run 0-3

Level 7 EARTH Insect/Effect 2400/2500

You can Special Summon this card (from your hand) to your opponent's field in Attack Position, by Tributing 1 monster they control. If your opponent controls a "Kaiju" monster, you can Special Summon this card (from your hand) in Attack Position. You can only control 1 "Kaiju" monster. When your opponent Normal or Special Summons a monster(s): You can remove 2 Kaiju Counters from anywhere on the field; until the end of the next turn, that monster(s) cannot attack and it has its effects negated. 

Level 7 is the best Level you want your Kaijus to have, so you can turn Magnet + Kaiju into Kitedrake. 

Run 1-3

Level 7 DARK Fiend/Effect 2800/2500

You can Special Summon this card (from your hand) to your opponent's field in Attack Position, by Tributing 1 monster they control. If your opponent controls a "Kaiju" monster, you can Special Summon this card (from your hand) in Attack Position. You can only control 1 "Kaiju" monster. Once per turn: You can remove 2 Kaiju Counters from anywhere on the field; Special Summon 1 "Radian Token" (Fiend/DARK/Level 7/ATK 2800/DEF 0), but it cannot be used as Synchro Material. 

The other Level 7 Kaiju.

Run 1-3

Level 1 WIND Machine/Tuner/Effect 0/0

Cannot be used as Synchro Material except for a Synchro Summon by its own effect. During your Main Phase, if this card is Normal or Special Summoned: You can target 1 face-up monster your opponent controls; immediately after this effect resolves, Synchro Summon 1 WIND Synchro Monster using only this card you control and that monster. You can only use this effect of "Speedroid Maliciousmagnet" once per turn. 

The main piece in this build. Since you're running Kaijus, you don't have to worry about whether or not the opponent will leave something on field that you can steal.

Run 1-2

Level 9 LIGHT Thunder/Effect 3300/2100

You can Special Summon this card (from your hand) to your opponent's field in Attack Position, by Tributing 1 monster they control. If your opponent controls a "Kaiju" monster, you can Special Summon this card (from your hand) in Attack Position. You can only control 1 "Kaiju" monster. Once per turn: You can remove 3 Kaiju Counters from anywhere on the field; your opponent cannot activate cards or effects for the rest of this turn, also this card can make up to 3 attacks on monsters during each Battle Phase this turn.

Level 9 is the second-best Level for Magnet, since it makes Baronne.

Run 0-3

Normal Spell

Destroy as many monsters on the field as possible, then Special Summon in Attack Position, 2 "Kaiju" monsters with different names from your Deck (1 on each side), but they cannot change their battle positions, and must attack, if able. During your Main Phase, except the turn this card was sent to the GY: You can banish this card from your GY; add 1 "Kaiju" monster from your Deck to your hand. You can only activate 1 "Interrupted Kaiju Slumber" per turn. 

Boardbreaker that sets up for Magnet.

Run 3